Fitbit has everything I need, the steps, the Heart Rate, it has all of my exercising modes, and it has a fair price. It has a rather simplistic User interface, which I really like to be honest. Highly recommened!
Strava - The #1 app for runners and cyclists
iFit – Workouts at Home - iFit – Workouts at Home app allows users to access an extensive collection of thousands of home workouts with advice and motivation from world-class fitness trainers.
Lose it! - Snap a photo of your food to get nutritional facts
BitGym - Virtual Cardio Tours. No heart rate sensor of special hardware required.
SmartHealth - SmartHealth is a health and fitness app that effectively monitors and records your sleep patterns and various health-related parameters such as heart rate, blood pressure, etc.
FITIV Pulse - Taking heart rate data and fitness tracking to a new level.