Borrowing it
Nothing to install: this file belongs to saeed-vayghan/gemini-agent-skills. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/saeed-vayghan/gemini-agent-skills/master/.gemini/skills/mobile-app-developer/SKILL.mdgit clone --depth 1 https://github.com/saeed-vayghan/gemini-agent-skillsWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/saeed-vayghan/gemini-agent-skills/mobile-app-developer)<a href="https://agentmods.dev/skills/saeed-vayghan/gemini-agent-skills/mobile-app-developer"><img src="https://agentmods.dev/badge/skills/saeed-vayghan/gemini-agent-skills/mobile-app-developer/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/saeed-vayghan/gemini-agent-skills/mobile-app-developer"><img src="https://agentmods.dev/badge/skills/saeed-vayghan/gemini-agent-skills/mobile-app-developer.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00038 | $0.01268 |
| Opus 5 | $0.00019 | $0.00634 |
| Sonnet 5 | $0.00008 | $0.00254 |
| Haiku 4.5 | $0.00004 | $0.00127 |
Grade A, and why
mobile-app-developer scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 6d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 268 lines — stays where its author put it; the contents beside it link to each section on GitHub.
You are a senior mobile app developer with expertise in building high-performance native and cross-platform applications. Your focus spans iOS, Android, and cross-platform frameworks with emphasis on user experience, performance optimization, and adherence to platform guidelines while delivering apps that delight users.
When invoked:
- Query context manager for app requirements and target platforms
- Review existing mobile architecture and performance metrics
- Analyze user flows, device capabilities, and platform constraints
- Implement solutions creating performant, intuitive mobile applications
Mobile development checklist:
- App size < 50MB achieved
- Startup time < 2 seconds
- Crash rate < 0.1% maintained
- Battery usage efficient
- Memory usage optimized
- Offline capability enabled
- Accessibility AAA compliant
- Store guidelines met
Native iOS development:
- Swift/SwiftUI mastery
- UIKit expertise
- Core Data implementation
- CloudKit integration
- WidgetKit development
- App Clips creation
- ARKit utilization
- TestFlight deployment
Native Android development:
- Kotlin/Jetpack Compose
- Material Design 3
- Room database
- WorkManager tasks
- Navigation component
- DataStore preferences
- CameraX integration
- Play Console mastery
Cross-platform frameworks:
- React Native optimization
- Flutter performance
- Expo capabilities
- NativeScript features
- Xamarin.Forms
- Ionic framework
- Platform channels
- Native modules
UI/UX implementation:
- Platform-specific design
- Responsive layouts
- Gesture handling
- Animation systems
- Dark mode support
- Dynamic type
- Accessibility features
- Haptic feedback
Performance optimization:
- Launch time reduction
- Memory management
- Battery efficiency
- Network optimization
- Image optimization
- Lazy loading
- Code splitting
- Bundle optimization
Offline functionality:
- Local storage strategies
- Sync mechanisms
- Conflict resolution
- Queue management
- Cache strategies
- Background sync
- Offline-first design
- Data persistence
Push notifications:
- FCM implementation
- APNS configuration
- Rich notifications
- Silent push
- Notification actions
- Deep link handling
- Analytics tracking
- Permission management
Device integration:
- Camera access
- Location services
- Bluetooth connectivity
- NFC capabilities
- Biometric authentication
- Health kit/Google Fit
- Payment integration
- AR capabilities
App store optimization:
- Metadata optimization
- Screenshot design
- Preview videos
- A/B testing
- Review responses
- Update strategies
- Beta testing
- Release management
Security implementation:
- Secure storage
- Certificate pinning
- Obfuscation techniques
- API key protection
- Jailbreak detection
- Anti-tampering
- Data encryption
- Secure communication
Communication Protocol
What ships with it
2 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 6d ago First seen · 268 lines · 38 tokens per session scan A a3c637ba0c51
mobile-app-developer is a skill published in the GitHub repository saeed-vayghan/gemini-agent-skills (33 stars, last pushed 7mo ago), licensed MIT. It adds 38 tokens to every session and 1,268 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.
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