JacksonvilleApp & Custom Software Development in Jacksonville
Software development for Jacksonville. We build innovative mobile apps and websites for Northeast Florida businesses.
App369 is a founder-led software studio based in Miami, Florida. We build custom mobile apps, web platforms and AI features for businesses in Jacksonville and beyond, working remotely on Eastern Time.
- Fiverr
- 5.0 · 126 reviews
- Own product
- Workspace369
- Fixed-price offers from
- $450
Fixed-price services
Same fixed prices wherever you are
Fixed scope, fixed price, paid upfront. The work happens in writing; no call needed.
- App Fix Ticketfrom $450One reproducible bug in an existing mobile or web app, diagnosed and fixed.
- AI-Built App Rescuefrom $450A Lovable, Bolt or Cursor app checked end to end in 3 days, then its worst problems fixed at a fixed price.
- Web App MVP Sprintfrom $6,000A scoped web app MVP in Vue/Nuxt or React, with a fixed quote after a $450 written scoping.
- Monthly Dev Subscriptionfrom $1,495/monthOne development request at a time, most back in about 2 business days. Pause or cancel anytime.
Why App369
Why Jacksonville Businesses Choose App369
What Jacksonville teams should know before working with App369.
Serving Jacksonville, Jacksonville Beach, and Northeast Florida
Focus on finance, logistics, and healthcare sectors
Understanding of Jacksonville's business environment
What we build
Software Development Services in Jacksonville
From the River City to the beaches, we build software that helps Jacksonville businesses thrive in competitive markets.
Mobile Apps
iOS and Android apps built with Flutter from one codebase, from concept to App Store launch.
- iOS & Android
- Cross-Platform
- App Store Optimization
- Maintenance & Updates
Web Development
Fast websites and web applications, built for search and for phones first.
- Custom Design
- E-Commerce
- SaaS Applications
- SEO Optimization
Custom Software
Internal tools, integrations and back-office systems engineered around how your team already works.
- Enterprise Development
- API Integration
- Cloud Migration
- Technical Consulting
How it works
Our 4-Phase Development Process
A written scope and four clear phases keep Jacksonville projects predictable.
Discovery
Understanding your vision, goals, and market requirements through stakeholder interviews and competitive analysis.
Design
Creating clear UI/UX with interactive prototypes you can click through before we build.
Development
Building with Flutter, Vue.js, Node.js, and GCP using 2-week Agile sprints with weekly milestone reviews.
Launch
Deployment to production with crash and uptime monitoring and ongoing maintenance.
Technologies
- Flutter
- TypeScript
- Node.js
- GCP
- Firebase
- Vue
- JavaScript
- Python
Questions
Frequently Asked Questions
How long does a typical project take?
It depends on scope. As a rough guide, a marketing website takes 4-8 weeks, a web application 2-4 months, and a mobile app 3-6 months. Every Jacksonville project starts with a written scope and milestone plan, so you know the timeline before any build work starts.
Do you provide ongoing support?
Yes. After launch we offer maintenance that covers bug fixes, iOS and Android OS updates, security patches, dependency upgrades and small feature work, so your Jacksonville app keeps working as the platforms change.
What's your pricing model?
App369 uses project-based pricing with a 50/50 payment structure: 50% upfront and 50% on completion. Current ranges are published on our fee structure page, and smaller fixed-price packages are available for well-defined work.
Can you work with existing projects?
Yes. We take over existing codebases, especially Flutter and Firebase apps, for code audits, bug fixes, new features and migrations. Jacksonville businesses with an app that stalled or a developer who left can start with an audit before committing to a larger build.
What technology do you use?
Mostly Flutter for iOS, Android and web apps from one codebase, Firebase and Google Cloud for backends, and Vue/Nuxt for websites. For AI features we integrate large language models for assistants, document extraction and automation.
Your Development Partner
Simon Dziak
As founder of App369, I personally oversee every project we take on, from scoping to launch. I build with Flutter, Firebase and Google Cloud, and I also built and run Workspace369, a client-management platform for freelancers and small businesses. Based in Miami, Florida, we serve clients across Jacksonville and nationwide.
Start Your Jacksonville Project
Fiverr reviews / 95 on app work
What buyers said about working with Simon
“I am so happy that this app finally came to life. Szymon’s work was outstanding and professional. He was prepared with solutions for problems I had and even did more than I asked for. I already hired Szymon for more projects and am excited for the future.”
A buyer in the United States, October 2020. App development on Fiverr “Can’t wait to use and work with this app. Very excited to bring it to market. Szymon took care of all the details I asked for and over delivered. Would recommend him to anyone.”
A buyer in the United States, October 2020. App development on Fiverr “Szymon did an amazing job and even over preformed my original expectations. He knew exactly what I needed and delivered in a professional manner. Thank you. Will be returning here for sure!!”
A buyer in the United States, October 2020. App development on Fiverr
Read the whole story
- Sixteen five-star reviews from one buyer: mobile apps, app design and a Shopify store (Mark, United States)
- A large custom app build, delivered on the back end and the front end (A buyer in the United States)