Groupon said today that it has launched Snap, a new mobile app that gives people cash for buying certain groceries and packaged goods found at everyday supermarkets. The app works in both the U.S. and in Canada on both Android devices and iPhones. To earn money, consumers must buy items listed in the app, and then take a picture of their receipt to verify the purchase. Once a user accumulates $20 in cash back, they’re paid out.Â