Fitness Tracking Wearable Development

I'm seeking an experienced developer to create a fitness tracking wearable device. The device should focus on heart rate monitoring and activity recognition, specifically for running and gym workouts.

Key requirements include:
- Accurate heart rate monitoring
- Activity recognition for running and gym activities
- User-friendly interface
- Durable and comfortable design

Ideal skills and experience:
- Background in wearable technology development
- Expertise in fitness tracking algorithms
- Experience with UI/UX design for wearables
- Knowledge of materials suitable for fitness devices

Please provide samples of previous work in wearable tech.