You can not only track the money you lend or borrow from people, but you can track anything. For example, if you lent out a DVD, borrowed a book, or just owe someone a nice dinner for helping you move, you can track it in the Borrow & Lend App.
I wrote this application entirely in Swift and using only Apple provided libraries, so no need for CocoaPods or any other 3rd Party library. My secondary motivation for writing this App was to learn Swift and I learned a lot (which I'll be writing about soon).
Try the app out and let me know what you think. It's now available on the App Store.