| name | mobile-apps |
| description | Mobile application development skill - triggered when building mobile apps for Android, iOS, or both. Guides framework selection (React Native, Flutter, Swift, Kotlin, .NET MAUI), native features, app store submission, push notifications, and offline support. |
| allowed-tools | Read, Write, Edit, Glob, Grep, Bash, WebFetch, WebSearch, Agent |
Mobile Application Development Skill
When This Skill Activates
- User mentions: mobile app, iOS app, Android app, React Native, Flutter, Swift, Kotlin
- During
/implement when building for mobile
- When discussing app store, push notifications, offline mode
Framework Selection Guide
Ask First
- Target platforms? (iOS only, Android only, both)
- Team expertise? (JavaScript, Dart, Swift, Kotlin, C#)
- App type? (Content, utility, social, e-commerce, enterprise, game)
- Performance critical? (Animations, video, AR -> native or Flutter)
- Existing web codebase to share? (Yes -> React Native or PWA)
- Budget/timeline? (Tight -> cross-platform, Flexible -> native)
Framework Decision Tree
Both platforms + JS team? -> React Native (Expo recommended)
Both platforms + best UI? -> Flutter (Dart)
Both platforms + C# team? -> .NET MAUI
iOS only + best performance? -> Swift + SwiftUI
Android only + best performance? -> Kotlin + Jetpack Compose
Simple app + existing website? -> PWA (Progressive Web App)
Game or heavy graphics? -> Unity or Unreal Engine
Framework Comparison
| Framework | Language | Platforms | Performance | Native Feel | Hot Reload |
|---|
| React Native (Expo) | JS/TS | iOS + Android | Good | Good (native components) | Yes |
| Flutter | Dart | iOS + Android + Web + Desktop | Excellent | Custom (Material/Cupertino) | Yes |
| SwiftUI | Swift | iOS/iPadOS/macOS/watchOS | Excellent | Native Apple | Yes (Xcode) |
| Jetpack Compose | Kotlin | Android | Excellent | Native Android | Yes |
| .NET MAUI | C# | iOS + Android + Win + Mac | Good | Native | Yes |
| Kotlin Multiplatform | Kotlin | iOS + Android | Good | Native | Partial |
Mobile Architecture
UI Layer (SwiftUI / Compose / React Native / Flutter)
|
|-- Navigation (stack, tabs, drawer)
|-- State Management (Redux/Zustand, Riverpod/Bloc, SwiftUI @State)
|
Service Layer
|-- API Client (REST/GraphQL + auth tokens)
|-- Local Storage (SQLite, Realm, AsyncStorage, Hive)
|-- Push Notifications (APNs / FCM)
|-- Background Tasks (sync, upload, location)
|
Platform Layer
|-- Camera, GPS, Biometrics, Bluetooth, NFC
|-- Deep Links, Share Extensions, Widgets
Mobile-Specific Patterns
Offline-First Architecture:
- Local DB as source of truth (SQLite, Realm, Hive)
- Sync queue for pending changes
- Conflict resolution (last-write-wins or merge)
- Background sync when connectivity restored
Push Notifications:
- iOS: APNs (Apple Push Notification service)
- Android: FCM (Firebase Cloud Messaging)
- Backend: Send via Firebase Admin SDK or AWS SNS
- Handle: foreground, background, and killed states
Deep Linking:
- Universal Links (iOS) / App Links (Android)
- Custom URL schemes (myapp://screen/123)
- Deferred deep links (link before install -> open after install)
App Store Submission
| Apple App Store | Google Play Store |
|---|
| Account | $99/year | $25 one-time |
| Review | 1-7 days (strict) | Hours to 3 days |
| Guidelines | Apple Human Interface | Material Design |
| Privacy | App Privacy Labels required | Data Safety section |
| Payments | 15-30% commission (IAP required) | 15-30% commission |
| TestFlight/Beta | TestFlight (up to 10K) | Internal/Open testing |
Mobile Security
- Certificate pinning for API calls
- Biometric auth (Face ID / fingerprint)
- Secure storage (Keychain iOS / KeyStore Android)
- Root/jailbreak detection
- Code obfuscation (ProGuard/R8 for Android)
- No sensitive data in logs or screenshots
Mobile Performance
- App launch time < 2 seconds
- Smooth 60fps animations
- Memory management (avoid leaks)
- Image caching and optimization
- Lazy loading for lists (FlatList/ListView)
- Bundle size: iOS < 50MB, Android < 30MB (for fast downloads)
React Native (Expo) Recommended Stack
Expo SDK (managed workflow)
+ React Navigation (routing)
+ Zustand or Jotai (state)
+ TanStack Query (server state)
+ React Native Paper or Tamagui (UI)
+ Expo Notifications (push)
+ Expo SecureStore (secure storage)
+ Expo SQLite (local DB)
Flutter Recommended Stack
Flutter SDK
+ GoRouter (navigation)
+ Riverpod or Bloc (state management)
+ Dio (HTTP client)
+ Hive or Drift (local storage)
+ Firebase Messaging (push notifications)
+ Flutter Secure Storage
