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!

Splittable - Shared living made simple

ihatemoney - Manage your shared expenses, easily

Tricount - Manage and share expenses with friends

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

MoneyBuster - Multi-project shared budget manager able to sync with self hosted FOSS services