Flutter developmentFlutter App Development
Build your mobile app for iOS and Android from one codebase. App369 is a Flutter app development agency in Miami, Florida. We build production Flutter apps from a single Dart codebase for iOS, Android, and web, with Firebase and Google Cloud behind them. It's the same stack our founder uses to build and run Workspace369.
- Fiverr
- 5.0 · 126 reviews
- Own product
- Workspace369
- Fixed-price offers from
- $450
What we build
Flutter Development Services
01
Cross-Platform App Development
Build one Flutter codebase that deploys to iOS, Android, web and desktop. Flutter compiles to native machine code on mobile and draws its own UI, so screens look and behave the same on every platform without a second team.
02
Widget-Based UI Development
Flutter's composable widget system enables pixel-perfect, brand-consistent interfaces across platforms. We build custom widget libraries, complex animations, and adaptive layouts that follow Material Design 3 and Cupertino guidelines simultaneously.
03
Firebase Integration
Full backend integration with Firebase including Firestore real-time database, Authentication, Cloud Functions, Cloud Messaging for push notifications, and Crashlytics for monitoring.
04
State Management & Architecture
Scalable app architecture using Riverpod or BLoC patterns with clean architecture principles. Our approach ensures testable, maintainable code that scales from MVP to enterprise without requiring rewrites.
05
Custom Animations & Motion Design
Flutter's Impeller renderer, the default on iOS and on Android API 29+ since Flutter 3.27, precompiles shaders so animations don't stutter on first run. We build custom implicit and explicit animations, hero transitions, and micro-interactions that improve user experience beyond what standard native development offers.
06
Plugin & Package Development
When existing packages don't meet requirements, we build custom Flutter plugins using platform channels to access native iOS and Android APIs directly. Our plugins integrate with device hardware including cameras, Bluetooth, NFC, and biometric sensors.
How it works
Our process
Discovery & Requirements
We analyze your business goals, target platforms, and feature requirements to define the Flutter project architecture, select the right state management approach, and create a detailed development roadmap.
UI/UX Design & Prototyping
Simon designs platform-adaptive interfaces in Figma that follow both Material Design 3 and Cupertino guidelines, validated through interactive prototypes and user testing.
Flutter Development
Our Flutter developers build your app using clean architecture patterns, custom widget libraries, and Firebase integration. We implement CI/CD pipelines from day one for continuous delivery.
Testing & Quality Assurance
Comprehensive testing including unit tests, widget tests, and integration tests using Flutter's built-in testing framework. We test across multiple device sizes and OS versions.
App Store Deployment
We handle submission to both Apple App Store and Google Play Store from the single Flutter codebase, configure beta testing tracks, and optimize store listings for ASO.
Maintenance & Iteration
Ongoing support including Flutter SDK upgrades, dependency updates, performance monitoring via Firebase Crashlytics, bug fixes, and feature iterations based on user analytics.
Showcase
Apps built with Flutter
Flutter isn't a niche choice. Google's own Flutter showcase lists production apps such as:
- Google Pay: Google's payments app
- NotebookLM: Google's AI research notebook
- Toyota: in-vehicle infotainment
- SoFi: a finance super app
- Headspace: mental health and meditation
- MGM Resorts: the guest app
- LG Electronics: parts of webOS
- Universal Studios: next-generation experiences
Built by us
Workspace369
A client-work platform (CRM, proposals, invoicing, payments, scheduling, inbox and AI) built by App369's founder, Simon Dziak. One Flutter codebase with iOS, Android, web and desktop targets; GetX for state and routing; Firebase Auth, Firestore, Storage, Cloud Messaging, Crashlytics and App Check; Stripe for payments. The backend is TypeScript on Cloud Functions (2nd gen), split into 24 separately deployed Firebase codebases.
See it on the App Store (published by Workspace369 LLC) or read the Workspace369 case study. For more examples, see these apps built with Flutter.
Technologies
- Flutter
- Dart
- Firebase
- Google Cloud
- Riverpod
- BLoC
- GetX
- Stripe
Questions
Frequently asked questions
How much does a Flutter app cost?
It depends on scope: the number of screens, integrations, admin tools and how much backend work sits behind the app. Our free app cost calculator turns those choices into a range with every assumption listed, and our fee structure page shows how we price projects. One Flutter codebase usually costs less than two separate native apps because the UI and business logic are written once, though platform-specific work such as payments, push notifications and store setup is still done per platform.
Flutter vs React Native: which is better?
Both are solid. In the 2024 Stack Overflow Developer Survey, 9.4% of all respondents used Flutter and 8.4% used React Native. Flutter draws its own UI with its Impeller renderer and is written in Dart; React Native renders platform-native components and is written in JavaScript or TypeScript, which suits teams that already work in React. We build in Flutter because one codebase covers mobile, web and desktop with the same UI. Our Flutter vs React Native comparison goes deeper.
How long does it take to build a Flutter app?
It depends on scope. A focused MVP is measured in weeks to a few months; a full product with payments, admin tools and integrations takes longer. After the brief we send a milestone plan with dates, and our MVP development page explains how we cut scope to ship sooner.
Is Flutter suitable for enterprise applications?
Yes. The official Flutter showcase includes Google apps such as Google Pay and NotebookLM, Toyota's infotainment work, SoFi, MGM Resorts and LG's webOS. What makes a Flutter app enterprise-ready is the engineering around it: authentication, offline handling, automated tests, CI/CD and monitoring, which we set up from the first sprint.
Does Flutter support web and desktop apps?
Yes. Flutter's documentation lists Android, iOS, web, Windows, macOS and Linux as supported deployment platforms. Workspace369, which our founder built, keeps all of these targets in one Flutter project.
Can Flutter apps access native device features?
Yes. Flutter talks to native iOS (Swift or Objective-C) and Android (Kotlin or Java) code through platform channels, and pub.dev has packages for the camera, location, Bluetooth, biometrics, push notifications, NFC and more. When no package fits, we write a small platform-channel plugin that calls the native API directly.
Fixed-price services
Prefer a fixed price?
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.
- Firebase Security Rules Audit + Fix PR$950Tests whether one user can read or edit another customer’s data, and fixes what it finds.
- Firebase Cost-Cut Audit$750Where your Firebase or Google Cloud bill goes, with savings ranked by dollars a month and risk.
Start here
Build Once, Deploy Everywhere
Flutter runs apps from Google, Toyota and LG, and it runs our own product. Whether you need a startup MVP or a full-scale mobile application, try our free app cost calculator, get a detailed estimate by email, usually within one business day, or book a consultation ($100 per 15 minutes, paid upfront).
Fiverr reviews / 95 on app work
What buyers said about this kind of work
“Very detailed and professional. Understands full scope of project before advancing and has honest but critical feedback. such a pleasure with consultation and can't wait to get started.”
A buyer in the United States, July 2024. Custom order on Fiverr “Had a great consultation with Szymon. He knows his stuff and I have a deeper understanding of how my new mobile app can work.”
A buyer in the United States, April 2024. Custom order on Fiverr “Great consultation, had many of these types of meetings and definitely understood what nis needed to be done.”
A buyer in the United States, July 2023. Custom order 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)