FLUTTER / CROSS-PLATFORM MOBILE
PROPELOO engineers Flutter applications — from architecture and widget design through platform channel integration, state management, CI/CD and Play Store + App Store delivery. Flutter is the best cross-platform option when done correctly. Done incorrectly, it produces apps that look like neither iOS nor Android.
React Native uses a JavaScript bridge to communicate with native components — every JS-to-native call crosses this bridge, introducing latency. Flutter compiles Dart to native ARM code and renders via its own Skia/Impeller graphics engine — bypassing native components entirely. This means Flutter animations run at 60/120fps regardless of the native UI thread load. The tradeoff: Flutter widgets look like Flutter, not like iOS or Android. When designed well, this creates a consistent cross-platform experience. When designed carelessly, it produces apps that feel foreign on both platforms. PROPELOO uses platform-adaptive design patterns to make Flutter apps feel at home on each platform while sharing 95%+ of the codebase.
Feature-first folder structure, Riverpod for state management, Repository pattern, Freezed for immutable models, injectable for DI and go_router for navigation.
Implicit animations, explicit AnimationController, Rive for complex animations, CustomPainter for custom graphics, Impeller rendering engine and frame performance profiling.
MethodChannel for native code invocation (Swift/Kotlin), EventChannel for native streams, custom platform plugins for device-specific features not covered by pub.dev packages.
LayoutBuilder and MediaQuery for responsive layouts, platform-adaptive widgets (CupertinoApp for iOS feel, Material 3 for Android), different navigation patterns per platform.
Dio HTTP client with interceptors, JWT refresh, Retrofit-style type-safe API clients via dio_generator, WebSocket support, GraphQL via Ferry/Artemis.
Codemagic or GitHub Actions for automated builds, Shorebird for over-the-air Dart code updates (no store review), Fastlane for both store submissions.
Flutter is not "write once, run anywhere." It is "write once, adapt for each platform." The shared codebase is the business logic. The UI adapts.
Riverpod 2.0 with code generation (riverpod_generator) is type-safe, testable and handles async state well. Provider is legacy. Bloc/Cubit is appropriate for large teams that prefer explicit state machine patterns.
Axiom:
DatePicker, alerts, navigation back gestures and share sheets behave differently on iOS and Android. Flutter has CupertinoDatePicker and CupertinoAlertDialog for iOS-specific patterns. Ignoring this creates an app that iOS users find jarring.
Axiom:
Shorebird allows pushing Dart code updates to production without App Store or Play Store review — like React Native CodePush but for Flutter. Bug fixes ship in minutes, not days. This changes how you think about release quality gates.
Axiom:
Flutter Web uses CanvasKit rendering which is heavier than HTML (4MB+ initial load). Not appropriate for SEO-important content. Best for web apps that are extensions of mobile apps — admin panels, dashboard views for existing Flutter mobile users.
Axiom:
Impact: Riverpod for most apps. Bloc for teams that want explicit state transitions and testability.
Impact: go_router is the standard — deep linking, web URL support, nested navigation and shell routes.
Impact: Dio with custom interceptors for auth refresh and logging. Type-safe generated clients via dio_generator for large API surfaces.
Impact: Drift for relational data with complex queries. Hive for simple fast key-value storage. flutter_secure_storage for sensitive data.
Impact: Shorebird for bug fixes that cannot wait for store review. $20/month for production apps. Cannot update native code or assets.
Impact: iOS + Android for most apps. Add web only if your users need a web version and it is a dashboard/app extension, not a marketing/SEO site.
Beautiful cross-platform consumer app with shared business logic, platform-adaptive UI and both store deployment.
Cross-platform banking or payment app with biometric auth, secure storage, certificate pinning and platform-native payment flows.
Offline-capable field operations app for sales/service teams — local SQLite sync, camera integration, map with offline tiles and MDM deployment.
Bluetooth LE device control app via platform channels, real-time data visualisation with CustomPainter and cross-platform BLE protocol implementation.
Product catalogue, cart, payment integration (Stripe/Razorpay Flutter SDKs), push notifications and deep linking from marketing campaigns.
Fast cross-platform MVP — shared Dart codebase targeting iOS and Android simultaneously, 40% faster than building two native apps.
Stack: Flutter 3.x, Dart 3, Riverpod 2, go_router, Freezed
Stack: Dio, Drift, Hive, flutter_secure_storage, dio_generator
Stack: flutter_local_notifications, firebase_messaging, geolocator, camera, flutter_blue_plus
Stack: flutter_test, mocktail, integration_test, patrol
Stack: Codemagic, GitHub Actions, Fastlane, Shorebird, Firebase App Distribution
Stack: Firebase Crashlytics, Sentry, Firebase Analytics, Flutter DevTools
Uses iOS Keychain and Android Keystore for secure key-value storage. Tokens and sensitive data must be stored here, never in SharedPreferences or Hive without encryption.
Dio supports custom BadCertificateCallback and custom HttpClient for certificate pinning. Required for financial and health apps.
local_auth package wraps iOS Face ID/Touch ID and Android BiometricPrompt. Combine with flutter_secure_storage for biometric-protected token access.
flutter_jailbreak_detection checks for root/jailbreak. Required for financial apps. Note: OEM Android devices with custom ROMs can trigger false positives.
Flutter release builds with --obfuscate flag obfuscate Dart symbols. Combine with --split-debug-info for crash symbolication.
Platform channels are an IPC mechanism — validate all data received from platform channels as untrusted input. Do not expose sensitive native operations via MethodChannel without authentication.
Feature structure, Riverpod setup, navigation, data layer design and platform channel requirements.
Flutter widget library, platform-adaptive components, typography, colours and animation standards.
Feature development targeting iOS + Android simultaneously. Regular testing on physical devices.
Push notifications, biometrics, camera, location — platform channel development where needed.
Flutter DevTools profiling, jank elimination, startup time reduction and image memory optimisation.
Unit tests with mocktail, widget tests, integration tests on Firebase Test Lab.
App Store and Play Store submission via Codemagic, Shorebird setup for post-launch hotfixes.
Flutter compiles to native ARM, renders via its own engine — no JS bridge, consistent performance. React Native uses native components — feels more native per-platform but with JS bridge overhead. Flutter is better for: consistent cross-platform UI, complex animations, teams comfortable with Dart. React Native better for: teams with React/JavaScript expertise, apps needing a very native per-platform feel.
Business logic, API clients, data models, state management: ~95% shared. UI: 85-90% shared with platform-adaptive components for platform-specific patterns. Platform channels: 0% shared (written in Swift/Kotlin). Total: typically 80-90% code sharing vs building two separate native apps.
Yes, but with caveats. Flutter Web uses CanvasKit which downloads ~4MB of WASM — poor for first load on slow connections. Not SEO-friendly. Best for: dashboard/admin panels as extensions of mobile apps, not for public-facing web content. Use Next.js/React for public web, Flutter for the app extension.
Shorebird provides over-the-air code push for Flutter apps — push Dart code updates to production without App Store or Play Store review. Bug fixes reach users in minutes. $20/month for 5,000 active devices. Cannot update native code (Swift/Kotlin) or assets (images, fonts). Apple and Google permit code push within their guidelines.