Digit - SMS bot that monitors your bank account & saves you money
Inbox Creature - A super cute virtual pet, delivered right to your inbox.
Quicken - Stay in control of your monthly cash flows, budgets, and expenditures. Quicken provides a navigable interface where you can organize your debit, credit, and savings, and build good habits accordingly.
HippityPip - Teach phone numbers to kids
Money Manager Ex - Money Manager Ex is a free, open-source, cross-platform, easy-to-use personal finance software.
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!