Halfdollar - Free and elaborate spreadsheet budgeting.
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!
BeeWise - Automagically track your daily expenses. No manual entry.
Tricount - Manage and share expenses with friends
Verse Groups - Group expenses and payments, simplified.
Splittable - Shared living made simple