Real-time Incentivised Fitness Challenge App Development

I'm looking to create an engaging fitness challenge app where users can compete in PvP challenges and win rewards.

The app will feature:
- PvP challenges on step count, calorie burn, and distance covered (walking, cycling, running).
- Users pay an entry fee to participate.
- Various tracking methods: step count, calorie burn, distance (walking, cycling), and running speed.

Ideal skills and experience:
- Mobile app development (iOS/Android)
- Real-time data tracking and updating
- User-friendly UI/UX design
- Experience with fitness or gaming apps