The use of the "settle up" button to begin a payment is a bit confusing. Perhaps I'm just used to the way Splitwise used to work, but when I think "Settle up", I imagine seeing the list of who owes who. I actually ended up spending quite some time looking for the button to add a payment, before resorting to clicking on suspicious looking buttons and finding it under "settle up". Anyway, I think it would be more straightforward to to have an explicit "record a payment" button, just like the old days.