The Bookup App was an iOS app for readers of print books who wanted to swap their books for other books in their area, free of charge, and potentially make a new friend with a shared interest in reading. Bookup provided location-based book swapping functionality.

If you don't reread your books often, then they just end up gathering dust on a bookshelf. Why not give these books of yours a new life by "hooking them up" with a new owner in your geographic area?