Samsung has touted its Galaxy S4 as a “companion for life,” and a large part of that comes with its suite of S Health fitness features. The S4 comes with a built-in app that tracks your steps, how many calories you burn, your dietary habits, and your comfort level based on temperature and humidity.
While S Health is certainly useful for monitoring your daily fitness routine, it doesn't teach you how to get in shape. Workout Trainer by Skimble comes with thousands of free workouts ranging from weight lifting to yoga. The app acts as your own personal fitness instructor—complete with audio tutorials and instructional images.