React Native Developer — Background GPS + CarPlay Audio Alert App (iOS + Android)

I'm building a free iOS + Android app that alerts drivers through their car speakers before they reach a speed-safety camera. The web side already pulls live camera-location data from a public GeoJSON feed; I need an experienced React Native developer to build the mobile MVP. This is a real, funded project with a clear scope and a launch deadline. I'm looking for one strong developer to own the build. Core requirements (please confirm you've shipped these before): *Reliable background geolocation that keeps working when the app is backgrounded and the phone is locked (iOS + Android) *Local proximity/geofence triggers that fire an audio alert ~500–1000ft before a camera, only when moving above ~15mph *Audio routed to the active car output: CarPlay → Bluetooth → device speaker, via AVAudioSession *CarPlay (audio only, no custom UI — Driving Task entitlement already approved) and Android Auto support *Loads camera locations from a GeoJSON/ArcGIS feed (already working on the web side) *Simple onboarding: email signup, location permission, notification permission *Settings: alert distance and sound toggle Out of scope for v1: user accounts beyond email, social features, payments/subscriptions, cameras outside LA. Stack: React Native (one codebase, iOS + Android). You'll push to my private GitHub repo and test using my Apple Developer account (limited role). I own all accounts, keys, and the final publish. To be considered, your proposal must include: 1. A link to a LIVE App Store or Play Store app you built that uses background location (not a demo repo or simulator video) 2. One or two sentences on how you handle iOS killing background execution and keeping location/audio alive when the phone is locked 3. Two client references I can contact Budget is approximate and milestone-based. I'm open to discussing final scope and price with the right developer. Strong candidates will start with a small paid test task before the main build. I'll prioritize developers who address the background/locked-phone challenge directly. Generic proposals that skip the three items above won't be reviewed.