I was just looking for a good breathing app that lets me customize settings, thanks for this

That is most of what it does unless I’m misunderstanding what you mean. It can do general image manipulation stuff.

I used to use GIMP, but Krita has gotten advanced enough to where it can replace it for most things (at least that I would use it for).

I do it the old school way and just use stopwatches. Especially with running, it’s easy to just go by time and record it manually.

Joplin for notes, and Rclone drastically improves any cloud services.