Name: HIIT Timer - Work Rest Intervals
Author: RiversideArt

HIIT Timer runs interval work in rounds and sets. The default is the Tabata pattern, 20 seconds of work and 10 of rest, eight rounds, and you can change the work, the rest, the rounds, the sets and the rest between sets.

It shows the set, the round and the time left, and buzzes at each change.

Controls:
Select or tap: start or pause
Down: next phase
Up: back to the start of the phase
Back: pause
Menu: reset (press twice once it is running)
Vibration and beeps at each change can both be turned off in settings.

One-time purchase with no subscription, seven days free to try, and no permissions asked.