I need a simple timer app that would do just this: ring a bell (play a sound from an MP3 file preferably, but a build-in single-ring bell sound would do, it just has to be short and gentle, not an alarm) once every N minutes in a loop before I stop it. It must not require any intervention to stop ringing - just ring a bell and go on counting to the next time to ring.
It would also be great (yet is not necessary) if I could specify an irregular sequence of time intervals like 1 minute - bell - 15 minutes - bell - 7 minutes - bell - etc.
It should work nicely in background in parallel with media players like VLC but if it doesn't this is a tolerable flaw.
Most of the timer apps I could find in the Play store either focus on exercises or on meditation. Exercise-focused mostly are over-bloated, cost money and won't let you specify sounds. Meditation-focused often lack loop function.
The task seems simple and I can write such an app myself yet I would prefer to use an existing free app if it already exists.