Is there a timer for android that does not require manual shutdown?

Question

Android

Good afternoon.
We need such a timer for android, which after a given time would emit a short signal and turn itself off. It is desirable that the signaling time can be changed.
All the ones I've seen ring until you turn them off manually.

Answer 1

Look for fitness applications, for example, for boxing, there round 1 beats and that's it