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!
Cents - Put your spare change to work
/Tab - The simple way to split a bill among friends.
Dinngo - Splitting payments the fun and easy way
EquiTable - Split the bill fairly
BillGO App - The best way to pay and manage all your bills in an app