I think it would be great if we can setup a feature to periodically remind someone about their dues by sending an automated mail.
Or allow user to "gently" nudge a friend reminding about his due. I know I can send out a mail directly to do this, but I feel it is less awkward if the mail goes from a middle man like this app.

hmm, i think it would be bit awkward to allow automatic periodic "reminders" (except your friend who you want to remind opts into getting these periodic reminders) .. but i think a manual reminder which can be sent e.g. once a month would be feasible, do you think this is enough?

do you think the opposite would also be good to have: an option to send a periodic update to yourself with a list of all your debts? i'm not sure if anyone would use that one

thanks for your feedback