React Native Fitness Tracking App with Bluetooth Heart Rate Monitor Sync

Category: Mobile Development

Budget: 2500–2500 USDC

We are seeking an experienced mobile app developer to build a cross-platform fitness tracking application for iOS and Android using React Native. The core functionality requires connecting to standard Bluetooth Low Energy (BLE) heart rate monitors, logging real-time workout metrics (heart rate zones, active calories, duration, GPS route mapping), and securely syncing session data to our Firebase backend. Key deliverables include user authentication, a BLE device pairing workflow, live workout telemetry dashboards with dynamic charts, offline data caching with auto-sync, and exportable workout summaries. We already have complete Figma UI/UX designs and API specifications prepared. Deliverables include clean, documented source code, CI/CD pipeline setup for TestFlight and Google Play Internal testing, and a brief technical handover guide. The project timeline is estimated at 6 weeks with milestone reviews every two weeks.

Skills required

• React Native
• Bluetooth Low Energy (BLE)
• Firebase
• Mobile App Development
• TypeScript
• iOS Development
• Android Development

Milestones are funded into USDC escrow on Polygon before work begins.