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!
Pennies - Incredibly simple personal budgeting app for iOS
Splittable - Shared living made simple
Rocket Money - Find your paid subscriptions and cancel with one click
EquiTable - Split the bill fairly
Unspent - Track your spending money. Keep it simple.