GPS-Based Mobile Challenge App Developer

Seeking an experienced mobile developer or team to build an MVP for a GPS-based competitive challenge platform launching in Gaborone, Botswana. The app will let users discover nearby challenges, compete in Speed Point and Time Trial formats, and view live rankings and leaderboards. Key requirements include live GPS speed tracking, automatic start/finish detection, map-based challenge discovery, user and vehicle profiles, and an admin portal. This is not a basic CRUD app. Please share relevant examples of GPS or location-based apps you have built, your proposed technology stack, and your approach to implementing automatic Time Trial detection and measuring maximum speed in Speed Point challenges. A detailed MVP/RFP will be shared with shortlisted candidates.