With 22 preset 7-minute workouts to choose from, the J&J Workout app proves that gym class doesn’t have to last 45 minutes. The app is good for four-year old students through high-school seniors and has categories from Beginners to Advanced athletes. The app covers 72 exercises and shows how to properly do the exercise as it tells you what to do. Feel free to create your own smart exercise routines along with your choice of workout music. The app has gauges to track progress and its free, courtesy of the Johnson & Johnson Human Performance Institute. It’s available for iPhones, iPads, iPhones as well as Android systems.