- Sandbox Interval Stopwatch.
Interval Stopwatch is a versatile workout app designed for customizable, time-based training. Whether you're doing high-intensity interval training (HIIT), Tabata, or structured gym routines, the app makes it easy to build workouts with precise timing for reps, sets, and rounds.
Create and save your own workout templates, including rest periods and active intervals, all securely stored on your device. Ideal for anyone looking to streamline their fitness routine, Interval Stopwatch adapts to a wide range of training styles—from quick bodyweight sessions to complex strength circuits.