Cross-Platform Fitness Tracker App Development

I'm seeking an experienced smartwatch app developer to create a fitness tracking application for both Android and iOS platforms. The app will be focused on tracking fitness activities like running, cycling, and swimming.

Key Features:
- Multi-activity tracking: Running, cycling, swimming
- Health data collection: Heart rate, distance covered, calories burned

Ideal Skills & Experience:
- Proficiency in developing cross-platform apps for Android and iOS
- Strong background in fitness tracking technologies and health data integration
- Experience with user-friendly UI/UX design for wearable devices
- Knowledge of data security and privacy regulations

Please provide a portfolio showcasing similar projects.