iOS & Android Developer for Field Service App (Offline-First)

We're building a mobile app for field technicians and need an experienced native developer to take it from finished designs to production on both iOS and Android. The app lets technicians see assigned jobs, capture photos and signatures on-site, log parts used, and sync everything back to our backend. The hard part is reliability: techs often work with poor or no connectivity, so we need solid offline-first behavior with a sync queue that resolves conflicts gracefully once they're back online. Scope: — Job list and detail screens (Figma designs ready) — Offline capture (photos, forms, signatures) with background sync — Push notifications for new assignments — Secure login with role-based access — Integration with our existing REST API We have a working backend and final designs. Swift and Kotlin preferred, open to Flutter if you can show shipped, performant apps. Please share: — One app you shipped that handled offline sync, and how you resolved sync conflicts — How you keep battery use reasonable with background sync