Asking roommates to do chores or pay their debts can get touchy and awkward, and creating a solid chore assignment and financial tracking system can save you from many fights. Instead of a boring white board, make yours with an Arduino.
Chris at Rushpro's Own shared his design for such a system, and the video above should give you an idea of what it's capable of. He posted all of the software online. It'a slightly tricky build, but when it's done you can use the tiny portable computer to keep track of who last paid for food and who needs to do the dishes without any awkwardness or hurt feelings. For more info and the source code, check out the source link.