This has literally been done tens of not hundreds of times. It’s probably one of the go-tos for students in any kind of art/hci class. I did it myself back in 2007 as a student with a partnership with Telefonica and the Catalan government in Spain!
every "hackathon" I went to for years had some try a variation of this. and "bill-splitting" apps. but... wtf - you're an adult who can afford an apple smart phone. how many times are you "splitting a bill" and having to settle up with people such that this is such a burden that you'll want to use an app for that? that one truly flummoxed me, but every hackathon event (pre-covid) I went to had people talking about this sort of problem.