iOS: If you've ever loaned out a little cash to a friend and then forgot about it, PayMeBack might be the tool you need to keep track of who owes you money.It's not just for keeping track of unpaid dues; it lets you log your money borrowed as well. The tracking is nice, but what sets PayMeBack apart is how it stores locations for transactions to help you remember why you loaned someone money to begin with. It also lets you split payments among multiple people, which is a handy feature if you're keeping track of bills in a large household with several roommates. For billing purposes, it allows you to send them a gentle reminder directly from the app. There are other apps for iOS that do similar things, but PayMeBack's feature list and clean interface make it one of the best.
PayMeBack is 99c, but if used correctly could help you collect plenty in back pay from your friends.