Ability to mark certain expenses from people as paid. Rather than only being able to "settle it all up" at the very end or create 20+ "settle up" entries per expense paid separately. This would be a great way to consolidate payments and also reduce the bulk of having too many entries within the sheet when people transfer or pay partial amounts at a time.

eg. during a trip there are expenses before the trip occurs that some like to pay off before hand and some expenses during the trip are easier to be paid at the end.

Giving the option to record this easily would be a great help in managing debts and what exactly people have paid for without having to hold their own excel sheet