mobile-performance

mobile-performance is a skill for Claude Code, Codex from cosmicstack-labs/mercury-agent-skills. It costs 18 tokens per session (386 once invoked), scanned A, original, MIT.

A guide to improving the performance of mobile apps, including startup time, memory use, battery consumption, network requests, and frame rates. It covers profiling and diagnostic tools for iOS and Android.

In plain words
What is it for?
Use it to profile and optimize iOS or Android app startup, memory management, rendering, app size, and network performance.
Why use it?
It helps find and reduce slow launches, excessive memory use, battery drain, lag, and inefficient networking.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Use it to profile and optimize iOS or Android app startup, memory management, rendering, app size, and network performance.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/cosmicstack-labs/mercury-agent-skills/mobile-performance
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add cosmicstack-labs/mercury-agent-skills --skill mobile-performance
Clone the repo
git clone --depth 1 https://github.com/cosmicstack-labs/mercury-agent-skills

Made for: Claude Code, Codex.

Wrote 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.

agentmods badge for mobile-performance

README.md
[![agentmods](https://agentmods.dev/badge/skills/cosmicstack-labs/mercury-agent-skills/mobile-performance/github.svg)](https://agentmods.dev/skills/cosmicstack-labs/mercury-agent-skills/mobile-performance)
Your own site
<a href="https://agentmods.dev/skills/cosmicstack-labs/mercury-agent-skills/mobile-performance"><img src="https://agentmods.dev/badge/skills/cosmicstack-labs/mercury-agent-skills/mobile-performance/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.

agentmods 80×15 button for mobile-performance

Your own site · 80×15
<a href="https://agentmods.dev/skills/cosmicstack-labs/mercury-agent-skills/mobile-performance"><img src="https://agentmods.dev/badge/skills/cosmicstack-labs/mercury-agent-skills/mobile-performance.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 18 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 386 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00018 $0.00386
Opus 5 $0.00009 $0.00193
Sonnet 5 $0.00004 $0.00077
Haiku 4.5 $0.00002 $0.00039

Measured 8d ago against content hash 5b5710dfc364, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

mobile-performance 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 8d 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.

categories/mobile/mobile-performance/SKILL.md · 52 lines

What it actually says

Mobile Performance

Profile, diagnose, and optimize mobile app performance.

Key Metrics

Metric Target Tool
Cold Start <1.5s Xcode Organizer, Play Console
Warm Start <0.5s Systrace, os_signpost
Frames 60fps (16ms) Profile GPU, Perfetto
APK/IPA Size <50MB size-report, analyzer
Memory <150MB Xcode Memory Debugger, Memory Profiler
Network Latency <200ms p95 Proxyman, Charles

Startup Optimization

iOS

  • Reduce dynamic framework loading (prefer static libraries)
  • Lazy-load non-critical services
  • Profile with Instruments - App Launch
  • Use dispatch_once for singletons

Android

  • Apply App Startup library for content providers
  • Profile with Android Studio - Startup Profiler
  • Use baseline profiles (Android 12+)
  • Defer heavy init to background threads

Memory Management

  • Watch for retain cycles (weak/unowned references)
  • Image caching: use NSCache/LruCache with size limits
  • Monitor for OOMs in production with crash reporting
  • Release view controllers when off-screen

Network Optimization

  • HTTP/2 multiplexing for concurrent requests
  • Response caching with ETags
  • Prefetch data predictively
  • Compress with Brotli or gzip
  • Use Protocol Buffers over JSON for large payloads
Changes

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.

  1. 8d ago First seen · 52 lines · 18 tokens per session scan A 5b5710dfc364

Subscribe to this mod's changes

mobile-performance is a skill published in the GitHub repository cosmicstack-labs/mercury-agent-skills (471 stars, last pushed 17d ago), licensed MIT. It adds 18 tokens to every session and 386 once invoked, about $0.0001 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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