Everything but the code is finished - I have pixel-perfect Figma screens, polished copy, trained AI models, and fully documented REST endpoints waiting. What I need now is a fast, confident mobile developer who can turn all of that into a production-ready app for both iOS and Android within a strict three-day window. You are free to choose the stack you deliver quickest with Flutter, React Native, or any other tool you trust - as long as the end result meets Apple and Google store requirements. Core features to wire up: • Secure user authentication against my live OAuth-based API • Push notifications (Firebase Cloud Messaging endpoint is in place) • Passive background tracking of activity, accelerometer and GPS data, batched and sent to /sensor every N minutes with sensible battery management • Dashboard/Reports (touch-friendly interactions) The backend is fully operational, including staging and production environments, so you will focus solely on the app layer. Deliverables I’m expecting at hand-off: 1. Source repository with clean, well-commented code 2. TestFlight and Google Play Internal Testing builds 3. Final release builds ready for store submission 4. A brief README outlining build steps, environment variables, and any third-party libraries used We have a team on standby for quick clarifications, UX tweaks, and immediate testing, so communication will be fast-paced. If a 72-hour sprint excites you and you have proven experience shipping cross-platform apps, let’s get started right away.