Fitness Tracker Mobile App Development

I'm looking for an experienced mobile app developer to create a fitness tracking app for a startup. The app's main purpose is to track workouts, with specific features including an exercise log, progress tracking, and a workout timer. This app will be a stand-alone, without integration with other fitness devices or apps.

Ideal skills and experience for this project:
- Mobile app development (iOS and Android)
- Experience in creating fitness-related applications
- Knowledge of incorporating features like exercise logs and progress trackers
- Ability to create a simple, user-friendly stand-alone app