I built react-native-llm-meter, LLM cost tracking for Expo apps

If you ship Claude, GPT, or Gemini calls from a React Native app, you have a problem nobody's solved well, you don't know what's happening on the device. Server-side observability is excellent. Langfuse, Helicone, LangSmith, Stripe's token-meter all work amazingly for Node backends. None of them work cleanly in an Expo app they assume a server, they pull Node only APIs they don't ship AsyncStorage adapters and streaming breaks under Hermes. So I built it. Currently three providers, two storage adapters, streaming TTFT, de overlay, budget alerts, optional remote sink.