Komae

Komae is an app that helps you exchange free babysitting with people you know. You can add your friends to your "village" and list when you need a sitter and when you're available to sit. You get points when you babysit, and spend points when your friend watches your kid(s), so it's a fair way to trade babysitting! I'm not the maker, but just a user who thought it was a cool concept.