show numbers of friends
In Sweden we have a payment provider called "Swish" which lets you do direct bank transfers via mobile phone no. It would be awesome if you could actually see your friends numbers to be able to register a payment to them. This could also be solved by a free text box called "Payment information" where I could specify something like "Swish: +46733xxxx"
For others that don't use this, it would also be good to be able to show the number so you could give them a call to settle up.

Thanks for the suggestion! We’ve actually thought about something like this before – a text box to let people indicate how they’d like to get paid back (e.g. “Please send all payments via PayPal”, etc). It’s been on our list of possible improvements for a while, so I’ll bring it up again at our next meeting to remind people about it :)