I need a comprehensive athlete monitoring app developed for both iOS and Android platforms. The app should be able to track the following data: - Physical Activity: Workouts and practice sessions - Nutrition: Dietary intake - Sleep Patterns: Sleep quality and duration - Training Data: Specific metrics related to training sessions Ideal skills and experience: - Mobile app development for both iOS and Android - Experience with health and fitness tracking applications - Knowledge in data integration from various fitness APIs - UI/UX design for a user-friendly interface - Backend development to securely store and manage user data Please provide examples of similar work done and your approach to ensure data accuracy and security.