This app was mentioned in 2 comments, with an average of 0.50 upvotes
I believe it's this one: https://play.google.com/store/apps/details?id=ric.ov.RiichiCalc&gl=US
this might help you too https://play.google.com/store/apps/details?id=ric.ov.RiichiCalc&hl=en