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!
Carbon Visualiser - See your CO2 in burgers, basketballs, pufferfish and more
Splittable - Shared living made simple
Wren - Offset your carbon footprint by saving rainforests
EquiTable - Split the bill fairly
Website Carbon Calculator - Find out the how much CO2 your website emits