# App369

> App369 (App369 LLC) is a custom software development company based in Miami, Florida. It builds mobile apps (Flutter, with native Swift on iOS), web apps (Vue, Nuxt, React), backends and APIs (Node.js and TypeScript on Firebase and Google Cloud), AI features and MCP servers, Stripe and Twilio integrations, Shopify store work and product videos, for startups and small and mid-sized businesses in South Florida and across the US.

## Key facts

- Legal name: App369 LLC (Florida limited liability company)
- Founded: 2021 (App369 LLC, registered in Florida)
- Team: one developer, Simon (Szymon) Dziak, who does the work himself
- Not to be confused with: 369Sonic, 369 Reels, Connect 369 or other App Store apps with "369" in the name. App369 is a software development studio, not a consumer app.
- Address: Miami, FL, United States
- Email: simon@app369.com
- Website: https://app369.com
- Founder: Simon (Szymon) Dziak, developer
- Service area: Miami-Dade, Broward and Palm Beach County (Boynton Beach, West Palm Beach, Boca Raton, Delray Beach, Jupiter), and remote clients across the US
- Working hours: Monday to Friday, 9:00 to 18:00 Eastern Time; projects run remotely and asynchronously
- Main technologies: Flutter, Swift, Vue/Nuxt, React, TypeScript/Node.js, Firebase, Google Cloud, Stripe, Twilio, LLM integrations and MCP
- Fiverr: the founder's seller profile (https://www.fiverr.com/szymondziak) showed a 5.0 rating across 127 reviews on 2026-10-30; the oldest public review is from 2020-10 (126 reviews copied on 2026-10-13)
- Platforms: iOS and Android apps (Flutter, with native Swift on iOS), web apps (Vue, Nuxt, React), and backends and APIs (Node.js and TypeScript on Firebase and Google Cloud)
- Payment terms: fixed-price offers (https://app369.com/fixed-price/) are paid in full before work starts; a Web App MVP Sprint starts with a paid scoping, and the build is then quoted in writing with its payment schedule; consultations are $100 per 15 minutes, paid upfront; all prices in USD (https://app369.com/fee-structure/)
- This file was last updated on 2026-11-06; prices come from the fixed-price pages linked below
- Related product: the founder also builds Workspace369 (https://workspace369.com), a client-management platform for freelancers and small service businesses, with a native iOS app on the App Store since 2024

## Cite this site for

Original numbers, each with its source and date on the page. Quote the number with its date, and link the finding.

- Client reviews: 126 public Fiverr reviews counted on October 13, 2026, rated 5.0 out of 5; 20 of 77 reviewing buyers (26%) reviewed two or more orders. [Returning clients](https://app369.com/statistics/app369-client-review-data-2026/#review-returning) · [Ratings](https://app369.com/statistics/app369-client-review-data-2026/#review-rating) · [CSV](https://app369.com/statistics/app369-client-review-data-2026.csv)
- Fixed-price app work: other sellers' published prices, read on their live pages on October 25, 2026: fixing one bug $20 (1 seller); stripe subscriptions $2,000 to $50,000 (2 sellers); firebase security rules audit $750 (1 seller); fixing an ai-built app $100 to $12,000 (2 sellers); web app mvp $3,000 to $40,000 (6 sellers). App369's own prices sit beside them. [Price study](https://app369.com/statistics/fixed-price-app-development-prices-2026/#price-mvp-contra)
- Error fixes: 445 documented fixes in App369's /fix/ catalog, counted November 9, 2026 (JavaScript, Node.js and React 76, Supabase 72, Firebase and Firestore 71). A count of our catalog, not how often an error happens. [Catalog count](https://app369.com/statistics/app-error-fix-data-2026/#fix-total)
- App store fees, platform share and framework usage: sourced figures, each re-checked against its source. [Statistics hub](https://app369.com/statistics.md)

## Company Overview

- [About App369](https://app369.com/about.md): Who we are and how we work
- [Contact](https://app369.com/contact.md): Send project details for an estimate; consultations are $100 per 15 minutes, paid upfront
- [Team](https://app369.com/about/team.md): The founder and how projects are staffed
- [Portfolio](https://app369.com/portfolio.md): Showcase of delivered projects
- [Case Studies](https://app369.com/case-studies.md): Project breakdowns with verifiable facts only
- [Workspace369 case study](https://app369.com/case-studies/workspace369.md): How the founder built a Flutter + Firebase SaaS (iOS and web, 24 Cloud Functions codebases): features, architecture and lessons
- [QuoteIQ case study](https://app369.com/case-studies/quoteiq.md): a contractor CRM (Flutter, Nuxt, Firebase, Stripe payments, Twilio messaging) with 3,400+ App Store ratings, where the founder worked as an independent contractor through App369 from 2022 to 2026
- [3693 case study](https://app369.com/case-studies/3693-music-app.md): a private Flutter music streaming app on Firebase, with the lessons from a 103-finding QA pass
- [saas-mcp-connector case study](https://app369.com/case-studies/saas-mcp-connector.md): an open-source MCP server with per-user scoping, confirmed writes and rate limits
- [Case study: one buyer, 16 Fiverr reviews](https://app369.com/case-studies/fiverr/mobile-apps-and-a-shopify-store-for-one-buyer.md): verbatim five-star reviews from one US buyer, 2020-2022: a mobile app submitted to both stores, app design and a Shopify store
- [Case study: a large custom app build](https://app369.com/case-studies/fiverr/large-custom-app-build.md): five verbatim five-star Fiverr reviews from one US buyer in 2022
- [Case study: repeat Shopify orders](https://app369.com/case-studies/fiverr/shopify-store-repeat-orders.md): five verbatim five-star Fiverr reviews from one buyer: four on Shopify work, then one on an app
- [Florida app developers](https://app369.com/locations/florida.md): How App369 works with Florida businesses, plus Florida data-breach and privacy rules

## Services

- [All Services](https://app369.com/service.md): Overview of software development services
- [Mobile App Development](https://app369.com/service/mobile-apps.md): iOS and Android app development
- [Web App Development](https://app369.com/service/web-apps.md): Full-stack web applications
- [UI/UX Design](https://app369.com/service/ui-design.md): User interface and experience design
- [Consultations](https://app369.com/service/consultations.md): Technical consulting and advisory, $100 per 15 minutes, paid upfront
- [Fixed-Price Offers](https://app369.com/fixed-price.md): Fixed scope, fixed price, paid upfront: App Fix Ticket for mobile or web apps ($450 diagnosis, $1,200 fix), AI Feature or Agent Build ($2,500), Stripe Billing Fix and Setup ($950), Web App MVP Sprint (from $6,000 after a $450 scoping), API Integration ($1,200), Firebase Security Rules Audit + Fix PR ($950), MCP Connector for your SaaS ($2,500), Workspace369 setup, done for you ($450 Solo Setup for freelancers, $1,500 Team Setup for small agencies), SaaS Launch Video ($1,500, 60-second motion graphics), Shorts-as-a-Service ($1,500/month for 12 Shorts, $600 pilot pack), Firebase Cost-Cut Audit ($750), Shopify Speed & Checkout Tune-Up ($750), AI-Built App Rescue ($450 Launch Check, then a $1,950 Rescue Sprint), AI Agent Engineering Setup ($750 Diagnostic, then a $4,500 to $9,500 Setup Sprint), Monthly Dev Subscription ($1,495/month Starter, $3,995/month Studio)
- [Ongoing Maintenance](https://app369.com/service/ongoing-maintenance.md): Post-launch support and updates
- [Flutter Development](https://app369.com/service/flutter-development.md): Cross-platform Flutter apps
- [Backend & API Development](https://app369.com/service/backend-development.md): Node.js and TypeScript backends on Firebase and Google Cloud: APIs, data models, background jobs, security rules, cloud cost
- [Payments & Integrations](https://app369.com/service/payments-integrations.md): Stripe subscriptions, checkout and Connect payouts, Twilio texting and calls, email and calendar integrations
- [SEO, GEO & AEO Services](https://app369.com/service/seo-geo-aeo.md): AI citation audits, structured data, answer-ready pages, AI crawler rules and llms.txt setup for SaaS and service businesses
- [Lovable, Bolt & Replit App Fixes](https://app369.com/service/lovable-bolt-replit-app-fix.md): sign-in, data access, Stripe and deploy problems in AI-built apps, through the AI-Built App Rescue Launch Check or the App Fix Ticket
- [Supabase RLS Fixes](https://app369.com/service/supabase-rls-fix.md): row-level security, user_metadata policies, storage reads and October 30, 2026 grants, found and fixed before launch
- [Hire a Lovable Developer](https://app369.com/service/hire-lovable-developer.md): when Lovable can fix it and when to bring in a developer, what to ask and hand over, and fixed prices through the Launch Check or the App Fix Ticket
- [Hire a Bolt Developer](https://app369.com/service/hire-bolt-developer.md): what Bolt's own audits and version restore cover, moving to Supabase, hosting choices, what to hand over, and fixed prices through the Launch Check or the App Fix Ticket
- [Hire a Replit Developer](https://app369.com/service/hire-replit-developer.md): what a publish changes in the production database, what a rollback can't restore, what to hand over, and fixed prices through the Launch Check or the App Fix Ticket
- [Hire a FlutterFlow Developer](https://app369.com/service/hire-flutterflow-developer.md): which FlutterFlow plan lets a developer see the exported code, where fixes go so the next FlutterFlow push doesn't overwrite them, and fixed prices through the App Fix Ticket or the Firebase Security Rules Audit
- [Hire a Stripe Developer](https://app369.com/service/hire-stripe-developer.md): what a Stripe developer sets up (plans, Checkout, a signed and idempotent webhook handler, the customer portal, failed-payment rules, test clocks), three checks from Stripe's docs, published hourly rates against App369's fixed Stripe Billing price
- [Hire a Firebase Developer](https://app369.com/service/hire-firebase-developer.md): what a Firebase developer fixes (leaking security rules, growing bills, failing Cloud Functions, sign-in errors, Firestore quotas), three checks from Firebase and Google Cloud docs, published hourly rates against App369's fixed Rules Audit, Cost-Cut Audit and App Fix Ticket prices
- [Hire a Supabase Developer](https://app369.com/service/hire-supabase-developer.md): what a Supabase developer fixes (Row Level Security, exposed secret keys, auth sessions, Edge Functions, migrations), three checks from Supabase's docs, published hourly rates against App369's fixed Launch Check and App Fix Ticket prices
- [SaaS Development](https://app369.com/service/saas-development.md): a scoped first SaaS version in about 4 weeks, Stripe subscriptions tested with test clocks, team accounts with separate customer data, integrations, an MCP connector and monthly work after launch, at fixed prices
- [Hire an AI Agent Developer](https://app369.com/service/hire-ai-agent-developer.md): one AI feature or agent built in 10 business days from a one-page spec, with tools limited to approved actions, a scored eval run of up to 50 cases and token cost logging, at a fixed price; plus MCP connectors for Claude and ChatGPT
- [iOS Development](https://app369.com/service/ios-development.md): Native iOS app development
- [Android Development](https://app369.com/service/android-development.md): Native Android app development
- [PWA Development](https://app369.com/service/pwa-development.md): Progressive Web Apps
- [E-Commerce Development](https://app369.com/service/ecommerce-development.md): Online store solutions
- [MVP Development](https://app369.com/service/mvp-development.md): Minimum Viable Product for startups
- [AI Integration](https://app369.com/service/ai-integration.md): AI/ML integration services

## Fix an error

- [App Error Fixes](https://app369.com/fix.md): one page per error message, with causes and fixes checked against vendor docs
- [Supabase errors and fixes](https://app369.com/fix/supabase.md): every Supabase fix page on one page (auth, RLS, queries, Edge Functions, storage)
- [Firebase errors and fixes](https://app369.com/fix/firebase.md): every Firebase fix page on one page (Auth, Firestore, Functions, Storage, push)
- [Stripe errors and fixes](https://app369.com/fix/stripe.md): every Stripe fix page on one page (webhooks, subscriptions, Checkout, portal, test vs live)
- [Vercel and Next.js errors and fixes](https://app369.com/fix/vercel.md): every Vercel and Next.js fix page on one page (deploys, functions, env vars, redirects)

Every individual fix page, with a one-line summary, is listed in https://app369.com/llms-full.txt; the platform hub pages above list them by platform.

## Fixed-price offer pages

- [App Fix Ticket](https://app369.com/fixed-price/flutter-firebase-bug-fix.md): one bug in a Flutter, Swift, Kotlin, React, Vue, Firebase or Node.js app diagnosed ($450, 3 business days) or fixed as a pull request with a regression test ($1,200, 5 business days)
- [Firebase Security Rules Audit + Fix PR](https://app369.com/fixed-price/firebase-security-rules-audit.md): emulator test suite, severity report and a fix PR for Firestore and Storage rules ($950, 5 business days)
- [MCP Connector for your SaaS](https://app369.com/fixed-price/mcp-server-for-saas.md): an MCP server over an existing REST API so a SaaS works in Claude ($2,500; ChatGPT needs the OAuth sign-in add-on, +$1,000)
- [Workspace369 setup, done for you](https://app369.com/fixed-price/workspace369-setup.md): proposals, signatures, invoices and payments set up in Workspace369 ($450 Solo, $1,500 Team)
- [SaaS Launch Video](https://app369.com/fixed-price/saas-launch-video.md): a 60-second motion-graphics product video from real screens, plus 15-second and vertical cuts ($1,500)
- [Shorts-as-a-Service](https://app369.com/fixed-price/youtube-shorts-for-saas.md): twelve vertical motion-graphics Shorts a month, no filming ($1,500/month, $600 pilot pack)
- [Firebase Cost-Cut Audit](https://app369.com/fixed-price/firebase-cost-audit.md): every Firebase and Google Cloud service priced from measured usage, savings ranked by dollars and risk ($750)
- [Shopify Speed & Checkout Tune-Up](https://app369.com/fixed-price/shopify-speed-optimization.md): mobile speed and cart-to-checkout fixes on a duplicate theme, measured before and after ($750)
- [AI Feature or Agent Build](https://app369.com/fixed-price/ai-feature-development.md): one LLM feature or agent in an existing app or tool, with an eval set of up to 50 cases ($2,500, 10 business days)
- [Stripe Billing Fix and Setup](https://app369.com/fixed-price/stripe-billing-setup.md): Stripe subscriptions, webhooks, customer portal and failed-payment handling, tested in test mode ($950, 5 business days)
- [Web App MVP Sprint](https://app369.com/fixed-price/web-app-mvp.md): a Vue/Nuxt or React web app MVP in about 4 weeks, from $6,000, after a $450 written scoping with a fixed quote
- [Custom CRM Build](https://app369.com/fixed-price/custom-crm-build.md): a CRM or client portal built around how a business sells, on the Workspace369 backend or fully custom (Vue/Nuxt or React on Firebase), after a $450 written scoping (3 business days) that ends in a fixed build quote; the build is from $6,000; for building one yourself with an AI coding agent, Workspace369 is the backend (https://workspace369.com/build-a-crm-with-ai/)
- [API Integration](https://app369.com/fixed-price/api-integration.md): two systems connected through their APIs with retries, logs, alerts and tests ($1,200, 5 business days)
- [AI-Built App Rescue](https://app369.com/fixed-price/ai-app-rescue.md): apps built with Lovable, Bolt, Cursor, Replit, v0, Claude Code or Firebase Studio checked end to end (sign-in, data access, keys, Stripe, deploys) in a $450 Launch Check (3 business days), then up to 5 critical or high issues fixed in a Rescue Sprint ($1,950, or $1,500 after the credit)
- [Firebase Studio Migration Help](https://app369.com/fixed-price/firebase-studio-migration.md): Firebase Studio shuts down March 22, 2027 (Google); after Google's Move now export, the moved app's code, Firebase rules and deploy setup checked in a $450 Launch Check (3 business days), then fixes as pull requests at existing fixed prices: Rescue Sprint $1,950 ($1,500 after credit), App Fix Ticket $1,200 ($450 diagnosis), Rules Audit + Fix PR $950; the move itself and console steps stay with the workspace's creator
- [AI Agent Engineering Setup](https://app369.com/fixed-price/ai-agent-engineering-setup.md): repos made ready for Claude Code, Codex and Cursor agents: a written Diagnostic ($750, 5 business days, no calls, credited to the Sprint), then a Setup Sprint ($4,500 to $9,500, quoted in the report) with repo instructions, shared skills, commit gates, one worktree per agent and spend tracking
- [Monthly Dev Subscription](https://app369.com/fixed-price/monthly-dev-subscription.md): development requests on a monthly plan, one at a time, most back in about 2 business days, as pull requests: Starter $1,495/month (one app or website), Studio $3,995/month (up to 3); pause or cancel anytime
- [AI Search Visibility Audit](https://app369.com/fixed-price/ai-search-visibility-audit.md): 30 buyer questions run 3 times each in ChatGPT, Perplexity, Google AI Overviews and Gemini, who gets cited, and ranked fixes, $750
- [SEO + GEO Fix Sprint](https://app369.com/fixed-price/seo-geo-fix-sprint.md): structured data, answer blocks, AI crawler rules, sitemaps, internal links, Core Web Vitals and 5 answer pages in 10 business days, $1,950
- [Monthly AI Search Growth](https://app369.com/fixed-price/ai-search-growth.md): 4 answer-ready pages, citation tracking on 30 questions and one link-earning asset a month, $1,500/month

## Free tools

- [AI App Security Check](https://app369.com/tools/ai-app-check.md): enter a live app's address to find secret keys shipped in its JavaScript (shown masked), the Supabase or Firebase project and tables its code names, and missing security headers; passive GET requests to that site only, nothing stored; for apps built with Lovable, Bolt, Cursor, Replit, v0 or Firebase Studio
- [Firebase Security Rules Checker](https://app369.com/tools/firebase-rules-checker.md): paste firestore.rules or storage.rules to find public paths, test-mode rules, sign-in-only checks, ownership takeovers and unvalidated writes; runs in the browser
- [Supabase Grants & RLS Checker](https://app369.com/tools/supabase-oct-30-checker.md): paste a Supabase migration to find tables that need a GRANT after the October 30, 2026 Data API change, tables with RLS off, policies of true, ungranted sequences and views that skip RLS; runs in the browser
- [Supabase RLS Policy Checker](https://app369.com/tools/supabase-rls-policy-checker.md): paste Supabase policy SQL to find policies of true, sign-in-only checks, user_metadata roles, storage buckets anyone can list or write to, and security definer functions anyone can call; runs in the browser
- [Google Play Deadline Checker](https://app369.com/tools/google-play-deadline-checker.md): paste Android build.gradle and settings.gradle files to check Google Play's target API 36, 16 KB page size (AGP, NDK) and Play Billing Library 8 and 9 deadlines, with a date and fix for each; runs in the browser
- [App Handover Checklist](https://app369.com/tools/app-handover-checklist.md): for switching app developers or agencies; pick the services an app uses (App Store, Google Play, Expo, Firebase, Supabase, Stripe, RevenueCat, GitHub, Lovable, Bolt, Vercel, Netlify, domain) to get ordered ownership-transfer steps sourced from each vendor's help pages, plus a request message for the outgoing developer; runs in the browser
- [Fixed-Price Offer Finder](https://app369.com/tools/fixed-price-offer-finder.md): pick a problem (one bug, an AI-built app that breaks with real users, a high Firebase bill, Stripe subscriptions, a new web app, AI search visibility) and see which App369 fixed-price offer covers it, with its price; includes a table of every offer by the problem it solves
- [Firebase Shutdown Checker](https://app369.com/tools/firebase-shutdown-checker.md): paste dependency files, firebase.json or server and CI code to find the legacy FCM send API, Dynamic Links, Extensions, Firebase ML, FCM InstanceId APIs and Test Lab, with the shutdown date and fix for each; runs in the browser
- [Meta Graph API Version Checker](https://app369.com/tools/meta-graph-api-version-checker.md): paste app or server code and dependency files to find the Graph API and Marketing API versions you call, with the Available Until date for each, unversioned calls and Facebook SDK notes; runs in the browser
- [Fitbit and Google Fit Shutdown Checker](https://app369.com/tools/fitbit-google-fit-shutdown-checker.md): paste dependency files or app and server code to find calls to the legacy Fitbit Web API (turned off November 2, 2026) and the Google Fit APIs (supported until the end of 2026), with the replacement for each; runs in the browser
- [Cloud Functions Node.js 20 Runtime Checker](https://app369.com/tools/cloud-functions-nodejs-20-runtime-checker.md): paste firebase.json, functions/package.json, gcloud deploy commands or Terraform to list the Cloud Functions and Cloud Run functions runtimes you deploy, with Google's deprecation and decommission dates (Node.js 20 decommissioned October 30, 2026) and what still runs after; runs in the browser
- [Auth0 Rules and Hooks to Actions Checker](https://app369.com/tools/auth0-rules-hooks-to-actions-checker.md): paste Auth0 Rules, Hooks or Terraform config to see what each line becomes in Actions (custom claims, callback errors, MFA, metadata, secrets, context fields, Hook triggers) and what needs rework (global auth0 object, global, redirects, account linking) before Rules and Hooks stop running after November 18, 2026; runs in the browser
- [Min Instances Cost Calculator](https://app369.com/tools/min-instances-cost-calculator.md): monthly idle cost of minimum instances on Cloud Functions (2nd gen) and Cloud Run from Google's us-central1 list prices
- [Lovable and Bolt Credits Calculator](https://app369.com/tools/lovable-bolt-credits-calculator.md): converts the Lovable credits or Bolt tokens already used on one problem into dollars at the plan's published rate and the top-up rate; prices dated and linked to the vendor pages.
- [Shopify App Script Checker](https://app369.com/tools/shopify-app-script-checker.md): paste a Shopify store's page source or theme.liquid to list third-party scripts, render-blocking tags, ScriptTag apps (Shopify stops running storefront script tags on March 1, 2027), app embeds and rendered snippets; runs in the browser
- [App Development Timeline Calculator](https://app369.com/tools/app-timeline-calculator.md): a phase-by-phase estimate of how long an app takes to build
- [Technology Stack Recommender](https://app369.com/tools/tech-stack-recommender.md): a suggested stack from your goals, platforms and requirements

## Buyer guides

Each guide compares what each company publishes on its own website, plus public directory profiles such as Clutch where the guide says so. App369 publishes them and is one of the companies listed, so they are documentation-based comparisons, not independent benchmarks. The date shows when the facts were last checked.

- [Best App Developers in Palm Beach County](https://app369.com/blog/best-app-developers-palm-beach-county-2026.md) (checked 2026-10-22)
- [Best App Development Companies in Boca Raton](https://app369.com/blog/best-app-development-company-boca-raton-florida-2026.md) (checked 2026-10-22)
- [Best App Development Companies in Delray Beach](https://app369.com/blog/best-app-development-company-delray-beach-florida-2026.md) (checked 2026-10-22)
- [Best App Development Companies in Miami](https://app369.com/blog/best-app-development-company-miami-florida-2026.md) (checked 2026-10-22)
- [Best App Developers in Tampa](https://app369.com/blog/best-app-developers-tampa-florida-2026.md) (checked 2026-10-22)
- [Best App Development Companies in Orlando](https://app369.com/blog/best-app-development-company-orlando-florida-2026.md) (checked 2026-10-22)
- [Best Flutter App Development Companies](https://app369.com/blog/best-app-development-company-flutter-2026.md) (checked 2026-10-26)
- [Best Toptal Alternatives for Hiring App Developers](https://app369.com/blog/toptal-alternatives-hiring-app-developers-2026.md) (checked 2026-10-27)
- [Best MVP Development Companies for Startups](https://app369.com/blog/best-app-development-company-mvp-2026.md) (checked 2026-10-22)
- [Best Web App Development Companies](https://app369.com/blog/best-app-development-company-web-apps-2026.md) (checked 2026-10-22)
- [Best Mobile App Development Companies](https://app369.com/blog/best-app-development-company-mobile-apps-2026.md) (checked 2026-10-22)
- [Best iOS App Development Companies](https://app369.com/blog/best-app-development-company-ios-2026.md) (checked 2026-10-21)
- [Best Android App Development Companies](https://app369.com/blog/best-app-development-company-android-2026.md) (checked 2026-10-21)
- [Best AI Integration Companies for Apps](https://app369.com/blog/best-app-development-company-ai-integration-2026.md) (checked 2026-10-21)
- [Best PWA Development Companies](https://app369.com/blog/best-app-development-company-pwa-2026.md) (checked 2026-10-21)
- [Build a CRM with AI, Hire a Developer, or Buy One?](https://app369.com/blog/build-a-crm-with-ai-hire-a-developer-or-buy-one-2026.md) (checked 2026-10-25): the three paths with published agency prices and AI tool prices, each sourced
- [Custom CRM Development Cost in 2026](https://app369.com/blog/custom-crm-development-cost-2026.md) (checked 2026-11-08): published prices from 5 agencies with page dates, App369's catalog price, running costs, and a 3-year HubSpot comparison

## Shutdown and migration guides

Dates come from each vendor's own documentation, linked in each guide's sources; the date shows when the old addresses were last tested.

- [App platform deadlines calendar](https://app369.com/calendars/app-platform-deadlines.ics) (checked 2026-10-28): an iCalendar feed with one all-day event per dated Google Play, Firebase, Google Cloud, Google Mobile Ads, Meta, Fitbit and Supabase deadline from these guides, each with its guide and primary source; the same data as JSON at https://app369.com/data/app-platform-deadlines.json
- [Supabase "permission denied" on new tables: the October 30, 2026 change and the fix](https://app369.com/blog/supabase-permission-denied-new-tables-october-30-2026.md) (checked 2026-11-01)
- [App Store and Google Play deadlines for 2026 and 2027: every dated requirement in one table](https://app369.com/blog/app-store-google-play-deadlines-2026-2027.md) (checked 2026-10-21)
- [Firebase deprecations: every shutdown date, 2024 to 2027](https://app369.com/blog/firebase-deprecations-shutdown-dates-2026.md) (checked 2026-10-21)
- [Firebase Studio is shutting down: moving your project out before March 22, 2027](https://app369.com/blog/firebase-studio-shutting-down-migrate-project-2027.md) (checked 2026-10-21)
- [Firebase Extensions are shutting down: replacing them with function kits by March 31, 2027](https://app369.com/blog/firebase-extensions-shutting-down-replace-2027.md) (checked 2026-10-21)
- [Firebase ML model hosting shuts down June 15, 2027: moving TensorFlow Lite models to Cloud Storage for Firebase](https://app369.com/blog/firebase-ml-model-hosting-shutting-down-migrate-2027.md) (checked 2026-10-21)
- [Firebase Test Lab is shutting down: moving tests to the Developer Device Platform by September 30, 2027](https://app369.com/blog/firebase-test-lab-shutting-down-alternatives-2027.md) (checked 2026-10-21)
- [FCM legacy API shutdown and the September 29, 2027 InstanceId deadline](https://app369.com/blog/fcm-legacy-api-shutdown-http-v1-migration-2026.md) (checked 2026-10-21)
- [SafetyNet is gone: moving to Play Integrity and App Check](https://app369.com/blog/safetynet-shut-down-play-integrity-app-check-2026.md) (checked 2026-10-21)
- [Google Sign-In for Android is deprecated: moving to Credential Manager](https://app369.com/blog/google-sign-in-android-deprecated-credential-manager-2026.md) (checked 2026-10-21)
- [Android Things shut down: what to run a device app on](https://app369.com/blog/android-things-shut-down-device-app-alternatives-2026.md) (checked 2026-10-22)
- [goo.gl shut down: which Google short links still work](https://app369.com/blog/google-url-shortener-goo-gl-shut-down-2026.md) (checked 2026-10-21)
- [Google Places API is Legacy: fixing LegacyApiNotActivatedMapError](https://app369.com/blog/google-places-api-legacy-legacyapinotactivatedmaperror-2026.md) (checked 2026-10-21)
- [Google Fit API deprecated: moving to Health Connect and the Google Health API](https://app369.com/blog/google-fit-api-deprecated-health-connect-2026.md) (checked 2026-10-24)
- [Flutter "Build failed due to use of deleted Android v1 embedding": the fix](https://app369.com/blog/flutter-deleted-android-v1-embedding-build-failed-2026.md) (checked 2026-10-21)
- [Flutter "applying Flutter's main Gradle plugin imperatively" error: the fix](https://app369.com/blog/flutter-gradle-plugin-applied-imperatively-fix-2026.md) (checked 2026-10-21)
- [Play Billing Library 7 deprecated: update to 8 by November 1, 2026](https://app369.com/blog/play-billing-library-7-deprecated-update-to-8-2026.md) (checked 2026-10-21)
- [Play Billing Library 9: migration guide and the August 31, 2027 deadline](https://app369.com/blog/play-billing-library-9-migration-deadline-2027.md) (checked 2026-10-21)
- [Google Play requires target API 36: the Android 16 update](https://app369.com/blog/google-play-target-api-36-android-16-requirement-2026.md) (checked 2026-10-21)
- [Flutter UIScene migration: fix launch crashes on Xcode 27](https://app369.com/blog/flutter-uiscene-migration-xcode-27-app-wont-launch-2026.md) (checked 2026-10-21)
- [Google Play 16 KB page size: fixing Flutter and Android apps](https://app369.com/blog/google-play-16kb-page-size-flutter-android-2026.md) (checked 2026-10-21)
- [Google Play contacts, location, call log and geofencing permission changes on January 27, 2027](https://app369.com/blog/google-play-contacts-permissions-policy-2027.md) (checked 2026-10-21)
- [iOS 27 SDK required from April 2027: the Xcode 27 checklist for Flutter and native iOS apps](https://app369.com/blog/ios-27-sdk-requirement-april-2027-xcode-27-flutter.md) (checked 2026-10-21)
- [Meta Graph API version expiry dates through 2027 (v21.0, v22.0, v23.0)](https://app369.com/blog/facebook-graph-api-version-expiry-dates-2027.md) (checked 2026-10-21)
- [Google Play Games Services v1 shutdown in 2027 and the move to v2](https://app369.com/blog/play-games-services-v1-shutdown-migrate-to-v2-2027.md) (checked 2026-10-21)
- [Google Awareness API deprecation (as early as January 2027) and Android alternatives](https://app369.com/blog/google-awareness-api-deprecated-2027-alternatives.md) (checked 2026-10-21)
- [Google Mobile Ads (AdMob) SDK deprecation and sunset dates by version, 2027](https://app369.com/blog/admob-google-mobile-ads-sdk-sunset-versions-2027.md) (checked 2026-10-21)
- [Google Play's memory, DEX and zero-tap sign-in requirements, February and April 2027](https://app369.com/blog/google-play-memory-dex-zero-tap-sign-in-requirements-2027.md) (checked 2026-10-21)
- [Sign in with Apple's new private.icloud.com relay domain, later in 2026](https://app369.com/blog/sign-in-with-apple-private-icloud-com-relay-domain-2026.md) (checked 2026-10-21)
- [Apple's regulated medical device status declaration for health apps, due early 2027](https://app369.com/blog/app-store-medical-device-status-declaration-2027.md) (checked 2026-10-21)
- [Apple's updated age rating questions: what to answer in App Store Connect](https://app369.com/blog/app-store-age-rating-questions-update-2026.md) (checked 2026-10-21)
- [ITMS-91053 and ITMS-91061: fixing Apple privacy manifest emails](https://app369.com/blog/apple-privacy-manifest-itms-91053-itms-91061-flutter-fix-2026.md) (checked 2026-10-21)
- [ITMS-90725 SDK version issue: rebuilding a Flutter app with Xcode 26](https://app369.com/blog/itms-90725-sdk-version-issue-xcode-26-flutter-2026.md) (checked 2026-10-21)
- [Android developer verification: what app developers must register](https://app369.com/blog/android-developer-verification-requirement-2026.md) (checked 2026-10-21)
- [Flutter Android build fails after AGP 9: built-in Kotlin migration](https://app369.com/blog/flutter-android-gradle-plugin-9-build-failed-fix-2026.md) (checked 2026-10-21)
- [ITMS-90683 missing purpose string: fixing Info.plist in Flutter apps](https://app369.com/blog/itms-90683-missing-purpose-string-info-plist-flutter-2026.md) (checked 2026-10-21)
- [JCenter and Bintray shutdown: fixing old Android and Flutter builds](https://app369.com/blog/jcenter-bintray-shut-down-fix-android-flutter-builds-2026.md) (checked 2026-10-21)
- [Builder.ai shut down: what to do with the app it built for you](https://app369.com/blog/builder-ai-shut-down-what-to-do-with-your-app-2026.md) (checked 2026-10-21)
- [What replaced Firebase Dynamic Links](https://app369.com/blog/firebase-dynamic-links-shutdown-deep-linking-2026.md) (checked 2026-10-21)
- [Parse, Kinvey and Realm Sync alternatives](https://app369.com/blog/parse-kinvey-backend-as-a-service-alternatives-2026.md) (checked 2026-10-21)
- [Realm is deprecated: which mobile database to use](https://app369.com/blog/realm-deprecated-mobile-database-alternatives-2026.md) (checked 2026-10-21)
- [Glitch shut down: where to host small web apps](https://app369.com/blog/glitch-shut-down-where-to-host-web-apps-2026.md) (checked 2026-10-21)
- [InVision shut down: design and prototyping tools](https://app369.com/blog/invision-shut-down-app-prototyping-tools-2026.md) (checked 2026-10-21)
- [ProgrammableWeb shut down: where to find and vet APIs](https://app369.com/blog/programmableweb-shut-down-api-directories-2026.md) (checked 2026-10-21)

## Comparison Guides

- [Flutter vs React Native](https://app369.com/compare/flutter-vs-react-native.md): Sourced decision guide with a 7-question helper
- [Custom vs Template](https://app369.com/compare/custom-vs-template.md)
- [Native vs Cross-Platform](https://app369.com/compare/native-vs-cross-platform.md)
- [In-House vs Agency](https://app369.com/compare/inhouse-vs-agency.md)
- [Flutter vs Swift](https://app369.com/compare/flutter-vs-swift.md)
- [Flutter vs Kotlin](https://app369.com/compare/flutter-vs-kotlin.md)
- [Agency vs Freelancer](https://app369.com/compare/agency-vs-freelancer.md)
- [App369 vs Freelancer vs Agency](https://app369.com/compare/app369-vs-freelancer-vs-agency.md): App369's listed prices for defined jobs, its one-developer risk, and when not to pick it
- [Custom vs No-Code](https://app369.com/compare/custom-vs-nocode.md)

## Resources

- [Blog](https://app369.com/blog.md): App development insights and guides
- [Glossary](https://app369.com/glossary.md): App development terminology explained
- [What is an app handover?](https://app369.com/glossary/what-is-an-app-handover.md): Moving an app's source code, store listings, backend and payment accounts and domain to the owner, so a new team can carry on without the old one
- [What is an app rescue?](https://app369.com/glossary/what-is-an-app-rescue.md): Taking over a broken, unfinished or abandoned app, finding out what state it is in and fixing what stops it working, launching or being maintained, instead of rebuilding
- [What is fixed-price app development?](https://app369.com/glossary/what-is-fixed-price-app-development.md): Scope and total price agreed in writing before work starts; anything outside the scope is quoted separately
- [What is a code audit?](https://app369.com/glossary/what-is-a-code-audit.md): An independent review of an app's code and setup that reports security holes, broken flows, cost leaks and maintenance risks, with evidence
- [Stripe memberships not auto-renewing? How to fix it before renewal day](https://app369.com/blog/stripe-memberships-not-auto-renewing-fix-2026.md) (checked 2026-10-27): three ways to move members who paid one-time Stripe payments to subscriptions, who has to enter a card again, the customer portal, Smart Retries and the webhooks that keep member status in sync, from Stripe's docs
- [How to switch app development teams without losing your code](https://app369.com/blog/switch-app-development-team-without-losing-code-2026.md) (checked 2026-10-27): the safe order while the old team still has the keys (owner roles on GitHub, GitLab, AWS, Google Cloud, Stripe, the domain and both app stores, then the contract, a code snapshot, an independent review and credential rotation), from the vendors' docs
- [App developer disappeared? What to do in the first 48 hours](https://app369.com/blog/app-developer-disappeared-what-to-do-2026.md) (checked 2026-10-28): proof to gather, the accounts and renewal dates to check, and who can move each account (App Store, Google Play, Firebase, Stripe, Supabase, GitHub, domain) when the developer won't reply
- [How to transfer a Firebase project to a new owner](https://app369.com/blog/transfer-firebase-project-new-owner-2026.md) (checked 2026-10-28): the Owner role (console only for outsiders), the billing account switch and who can make it, the Google Analytics property and the iOS push key, from Google's docs
- [AEO vs GEO vs SEO](https://app369.com/blog/aeo-vs-geo-vs-seo-2026.md) (checked 2026-10-22): What each term means and what it changes on your site, from Google, OpenAI, Perplexity and Bing docs
- [How to get your SaaS cited by ChatGPT and Perplexity](https://app369.com/blog/get-saas-cited-chatgpt-perplexity-2026.md) (checked 2026-10-22): Which AI search crawlers to allow, how to test them, and how to measure citations
- [Agent Tool Optimization: get your app picked in AI Mode, Gemini, ChatGPT and Claude](https://app369.com/blog/agent-tool-optimization-get-your-app-picked-2026.md) (checked 2026-11-01): How assistants choose an app's MCP tools, what Google, OpenAI and Anthropic reject, and an 11-point checklist
- [How to build an MCP server](https://app369.com/blog/how-to-build-an-mcp-server-2026.md) (checked 2026-11-08): A step-by-step TypeScript build over an existing REST API on the 2026-07-28 spec and SDK v2: tools, Streamable HTTP, Inspector tests and OAuth bearer checks
- [llms.txt: what it does and doesn't do](https://app369.com/blog/llms-txt-what-it-does-2026.md) (checked 2026-10-22): What the proposal is, who reads it, and why Google ignores it for Search
- [How to show up in Google AI Overviews](https://app369.com/blog/how-to-show-up-in-google-ai-overviews-2026.md): What Google documents for AI Overviews and AI Mode: indexing, snippet controls, Google-Extended and Search Console reporting
- [What an AI search visibility audit checks and costs](https://app369.com/blog/ai-search-visibility-audit-what-it-checks-cost-2026.md): Citation runs, per-bot crawler checks, red flags when buying, and 2026 market prices
- [Statistics](https://app369.com/statistics.md): App development data and market research
- [Fixed-Price App Development Prices 2026](https://app369.com/statistics/fixed-price-app-development-prices-2026.md) (checked 2026-10-25): What sellers publish for a bug fix, Stripe subscriptions, a Firebase rules audit, an AI-built app rescue and a web MVP, each read on the live page
- [App369 Client Review Data 2026](https://app369.com/statistics/app369-client-review-data-2026.md) (checked 2026-10-13): The 126 public Fiverr reviews on the profile that day, counted: returning buyers, where they are, what they bought and what reviews mention most
- [App Development Statistics 2026](https://app369.com/statistics/app-development-statistics-2026.md) (checked 2026-10-12): App Store and Google Play economics, store fees and review times, U.S. and worldwide mobile OS share, and framework usage, each sourced
- [Mobile App Market Data 2026](https://app369.com/statistics/mobile-app-market-data-2026.md) (checked 2026-10-17): App Store billings, Google Play safety figures, iOS vs Android share, smartphone ownership, cart abandonment and app retention studies, each sourced
- [Flutter Adoption Statistics 2026](https://app369.com/statistics/flutter-adoption-statistics-2026.md) (checked 2026-10-12): Stack Overflow survey usage vs React Native, Dart and JavaScript usage, GitHub stars, Impeller and supported platforms
- [AI-Built App Security Statistics 2026](https://app369.com/statistics/ai-built-app-security-2026.md) (checked 2026-11-08): Public scans of Lovable and Supabase apps, an audit of 200 vibe-coded apps, NVD and GitHub advisory counts; methodology and CSV
- [Tools](https://app369.com/tools.md): Interactive app development tools
- [App Development Cost Calculator](https://app369.com/tools/app-cost-calculator.md): Cost range by app type, platforms, features and who builds it, with every assumption listed
- [Flutter iOS build failed after an upgrade](https://app369.com/blog/flutter-ios-build-failed-after-upgrade-2026.md) (checked 2026-10-21): Fixing CocoaPods and Xcode errors after a Flutter upgrade
- [How to debug a Flutter and Firebase bug](https://app369.com/blog/how-to-debug-a-flutter-firebase-bug-2026.md) (checked 2026-10-21): Finding the root cause step by step
- [Firebase Security Rules guide](https://app369.com/blog/firebase-security-guide-2026.md) (checked 2026-10-21): Writing and structuring Firebase Security Rules
- [How to test Firebase Security Rules](https://app369.com/blog/how-to-test-firebase-security-rules-2026.md) (checked 2026-10-21): Testing rules with the Firebase Emulator
- [How to cut your Firebase bill](https://app369.com/blog/how-to-cut-your-firebase-bill-2026.md) (checked 2026-10-21): A line-by-line Firebase cost audit
- [Firebase Cloud Functions min instances cost](https://app369.com/blog/firebase-cloud-functions-min-instances-cost-2026.md) (checked 2026-10-21): What keeping instances warm costs
- [Figma to Flutter guide](https://app369.com/blog/figma-to-flutter-design-handoff-guide-2026.md) (checked 2026-10-21): Design tokens to ThemeData, ThemeExtension and golden tests
- [Lovable app rescue](https://app369.com/blog/lovable-app-rescue-2026.md) (checked 2026-10-22): 7 problems to fix in a Lovable app before launch, from open Supabase tables to edge functions
- [Bolt app rescue](https://app369.com/blog/bolt-app-rescue-2026.md) (checked 2026-10-22): 8 problems to fix in a Bolt app before launch, from open database tables to hosting limits
- [Replit app rescue](https://app369.com/blog/replit-app-rescue-2026.md) (checked 2026-10-24): 7 problems to fix in a Replit app before launch, from production secrets to rollbacks that don't restore data
- [Cursor app rescue](https://app369.com/blog/cursor-app-rescue-2026.md) (checked 2026-10-22): 7 problems to fix in an app built with Cursor before launch, from secret keys and unprotected server actions to invented packages
- [Base44 app rescue](https://app369.com/blog/base44-app-rescue-2026.md) (checked 2026-10-22): 8 problems to fix in a Base44 app before launch, from open sign-up and "All Users" data rules to backend functions anyone can run
- [v0 app rescue](https://app369.com/blog/v0-app-rescue-2026.md) (checked 2026-10-22): 8 problems to fix in a v0 app before launch, from the React2Shell patch and browser-exposed keys to database rules and rollbacks
- [Hire someone to finish your vibe-coded app](https://app369.com/blog/hire-developer-finish-vibe-coded-app-2026.md): freelancer, agency, builder partner or fixed price for a Lovable, Bolt, Cursor, Replit or v0 app, what each costs, what to check first and 10 questions to ask
- [Supabase security review before launch](https://app369.com/blog/supabase-security-review-before-launch-2026.md): the Security Advisor, then 10 checks in order: secret keys, RLS policies, user_metadata, views and security definer functions, October 30 grants, storage, Edge Functions, auth email, passwords and backups
- [Industries](https://app369.com/industries.md): Industry-specific software solutions
- [Technology](https://app369.com/technology.md): Our technology stack
- [Fee Structure](https://app369.com/fee-structure.md): Pricing and engagement models

## Locations

- [All Locations](https://app369.com/locations.md): Service areas across the US and internationally
- [Miami, FL](https://app369.com/locations/miami-florida.md) (home base)
- [Palm Beach County, FL](https://app369.com/locations/palm-beach-county-florida.md)
- [West Palm Beach, FL](https://app369.com/locations/west-palm-beach-florida.md)
- [Boca Raton, FL](https://app369.com/locations/boca-raton-florida.md)
- [Delray Beach, FL](https://app369.com/locations/delray-beach-florida.md)
- [Jupiter, FL](https://app369.com/locations/jupiter-florida.md)
- [Fort Lauderdale, FL](https://app369.com/locations/fort-lauderdale-florida.md)
- [Miami, FL](https://app369.com/locations/miami-florida.md)
- [New York, NY](https://app369.com/locations/new-york-new-york/)
- [Los Angeles, CA](https://app369.com/locations/los-angeles-california/)
- [London, UK](https://app369.com/locations/london-uk/)
- [Dubai, UAE](https://app369.com/locations/dubai-uae/)
- [Berlin, Germany](https://app369.com/locations/berlin-germany/)
- [Amsterdam, Netherlands](https://app369.com/locations/amsterdam-netherlands/)
- [Singapore](https://app369.com/locations/singapore/)
- [Shanghai, China](https://app369.com/locations/shanghai-china/)
- [Milan, Italy](https://app369.com/locations/milan-italy/)
- [Paris, France](https://app369.com/locations/paris-france/)
- [Zurich, Switzerland](https://app369.com/locations/zurich-switzerland/)
- [Tokyo, Japan](https://app369.com/locations/tokyo-japan/)
- [Sydney, Australia](https://app369.com/locations/sydney-australia/)
- [Toronto, Canada](https://app369.com/locations/toronto-canada/)
- [Stockholm, Sweden](https://app369.com/locations/stockholm-sweden/)
- [Seoul, South Korea](https://app369.com/locations/seoul-south-korea/)
- [Tel Aviv, Israel](https://app369.com/locations/tel-aviv-israel/)
- [Hong Kong](https://app369.com/locations/hong-kong/)
- [Riyadh, Saudi Arabia](https://app369.com/locations/riyadh-saudi-arabia/)
- [Munich, Germany](https://app369.com/locations/munich-germany/)

## Machine-readable

- [Full content](https://app369.com/llms-full.txt): the highest-priority pages as markdown, under 500k characters
- [AI usage policy](https://app369.com/ai.txt): identity, permissions, attribution and scope
- [Sitemap](https://app369.com/sitemap.xml): every indexable page with the date its content changed
- Every page also has a markdown version: add .md to its address (the home page is https://app369.com/index.md), or send Accept: text/markdown