Paribus - Find out for free if online stores owe you a refund!
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!
Lolli - Earn bitcoin when you shop online
Splittable - Shared living made simple
Slice Watch - Get an email when an item you've added drops in price 💸
EquiTable - Split the bill fairly