antigravity-claudekit/skills/ck-mobile-development/SKILL.md

name, description

name	description
ck-mobile-development	Build mobile apps with React Native, Flutter, Swift/SwiftUI, Kotlin/Jetpack Compose. Use for iOS/Android development, mobile UX patterns, offline-first architecture, and app store deployment.

Mobile Development

Production-ready mobile development across React Native, Flutter, Swift, and Kotlin.

When to Use

• Building iOS, Android, or cross-platform mobile apps
• Implementing mobile-first UX (offline-first, push notifications, deep linking)
• Making native vs cross-platform framework decisions
• Optimizing battery, memory, network for mobile constraints
• Deploying to App Store or Google Play

Don't Use When

• Building responsive web apps (use web frameworks instead)
• Desktop applications (use Electron or native desktop frameworks)
• Simple PWAs that don't require native capabilities

Framework Selection

Need	Choose
JavaScript team, web code sharing	React Native
Performance-critical, complex animations	Flutter
Maximum iOS performance, latest features	Swift/SwiftUI
Maximum Android performance, Material 3	Kotlin/Compose
Rapid prototyping	React Native + Expo
Gaming / heavy graphics	Native or Unity

Performance Targets

• Launch: <2s (70% abandon if >3s)
• Memory: <100MB typical screens
• Frame rate: 60 FPS (16.67ms/frame)
• App size: <50MB initial download
• Battery: <5% drain/hour active use

Architecture Patterns

• Small-medium apps: MVVM
• Enterprise: MVVM + Clean Architecture
• State: Zustand (React Native), Riverpod 3 (Flutter), StateFlow (Android)
• Sync: Offline-first with hybrid push/pull

Security (OWASP Mobile Top 10)

• OAuth 2.0 + JWT + Biometrics for auth
• Keychain (iOS) / KeyStore (Android) for secrets
• Certificate pinning for network security
• Never hardcode credentials or API keys

Testing Strategy

• Unit tests: 70%+ coverage for business logic
• E2E: Detox (React Native), XCUITest (iOS), Espresso (Android)
• Real device testing mandatory before release

Platform Guidelines

iOS (HIG): Tab bar, navigation bar, San Francisco font, safe areas, haptic feedback

Android (Material 3): Bottom nav, FABs, Roboto font, Material You dynamic colors, ripple effects

Deployment

• Fastlane for automation
• Staged rollouts: Internal → Closed → Open → Production
• CI/CD saves ~20% development time

Common Pitfalls

1. Testing only on simulators (real devices show true performance)
2. Ignoring platform conventions
3. No offline handling
4. Hardcoded credentials
5. Skipping accessibility (excludes 15%+ of users)

Resources

• React Native: https://reactnative.dev/
• Flutter: https://flutter.dev/
• iOS HIG: https://developer.apple.com/design/human-interface-guidelines/
• Material Design 3: https://m3.material.io/
• OWASP Mobile: https://owasp.org/www-project-mobile-top-10/