This app was mentioned in 2 comments, with an average of 1.50 upvotes
Damn, my search-fu was weak. That was seriously easy, dunno why I didn't find it earlier. Thanks for LMGTFY'ing that. ;)
Anyway, you're right, that app kinda sucks.
Silver lining: the listing for it led me to a couple other apps that suck less (and they're free):
https://play.google.com/store/apps/details?id=pl.w9.prana
https://play.google.com/store/apps/details?id=org.shepherd.breathewell
That's weird.
Anyways, here is the link: https://play.google.com/store/apps/details?id=pl.w9.prana