Yown It - Turn posts into purchases with a simple, lightning fast app

Splitwise - Splitwise is a free tool for friends and roommates to track bills and other shared expenses, so that everyone gets paid back. On the web, iPhone, and Android!

Grover - Rent electronics for a month & try it before you buy.

Dinngo - Splitting payments the fun and easy way

Lumoid Locals - Peer-to-peer marketplace for short-term gadget rentals

/Tab - The simple way to split a bill among friends.