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!
Streaks Workout - The personal trainer that you actually want to use.
Strava - The #1 app for runners and cyclists
Daily Yoga - 50+ yoga classes, 400+ workout poses, w/ HD video and music
Lose it! - Snap a photo of your food to get nutritional facts
cure.fit - At-home fitness app for strength, cardio, dance and yoga
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.