This app is handy interval timer that helps you keep track of your work and rest periods during your HIIT interval training and workouts. The application is very easy to use, enter the Work, Rest, Sets, Rounds and start workout. You can listen to music during workouts or use the timer in the background. There is also app on the Apple Watch that will allow you to monitor your heart rate during workouts.

Apple Watch app features:
- iCloud sync with iPhone
- integration with the Health app
- monitoring heart rate during workouts