Periodic email updates of amounts owing
If this service were to suddenly disappear (please no!) I would have little idea of how much money people owe me or vice versa. I could be left out of pocket $100s of dollars. It would be nice if you could elect to receive periodic summaries via email of amounts owing between all of your friends (weekly, monthly etc.). This way you wouldn't have to go as far back if something were to happen to your data.

Hey Clayton – we do send out monthly summaries by default, detailing your spending for the past month and your total balances. You can turn that option on or off from your user settings page.
We’re also considering adding a weekly summary option, so if that’s something you’re interested in, let us know!