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!
SplittyPie - Create event, add users and their expenses.
Kittysplit - The easiest way of sharing costs with a group of friends
Settle Up - SETTLE UP is an indispensable app for friends and flatmates who need to keep track of shared bills...
Clever:Split - Share expenses with friends, family or roommates
ihatemoney - Manage your shared expenses, easily