Be able to combine groups
I use this with my ex to track expenses. We need to able to split up daycare vs other expenses. However we try to stay even across both categories. Can we do this? Maybe via transfer to another category. In other words transfer debt or credit from one category to another.
Your app has all the features I need - it splits costs! And cleverly. However, I do agree with Anonymous - it would be even more useful to have the ability to manage people outside of groups, and select from this common set of people to build a group. For example, the "groups" I have are like mini categories - 'Loans', 'Trips', 'General' - I have a common contact in all three groups, but I would like to see the total amount for the same person across all three groups in a contact overview screen.
Though I can easily just estimate the net tally for one person across groups, as I don't have too many groups yet, some form of overall people management would be part of the proverbial icing on the cake of this well designed app. Nice work.
It may be very complex to implement, but ideally the "people" should be managed from outside the groups, and then you would have the persons "position" (owing money/owed money) in each group, or in a series of groups... That way we can split for example trips which have some people the same, and others different using costsplit. I fear this may require an entire redesign and maybe rewrite of the core of the app, but it would be extremely nice... (Allow "me" to know how much I owe in all groups may already be a beginning, but having the identity of the people and their overall balance sensitive to all groups they are in would be cool...) This requires some thought, as a person may not be in all groups on one device, and also may belong to other groups that not everyone see, so some "server magic" would need to be involved...