Want to Torch Calories at Home? Try a HIIT Workout From One of These Top-Rated Apps

Cost: Free

Don't let the name fool you — the J&J Official 7-Minute Workout app offers preset workouts ranging from seven to 32 minutes in length. It also suggests "smart" workouts based on your fitness level and goals, and allows you to build your own routines using the app's vast collection of exercises. You'll love the focus on warming up, too — it's crucial to preventing injury, especially during high-intensity sessions.