Building off of the recent acquisition of a company called SnapSaves, Groupon is today unveiling an app in the U.S. called Snap that gives shoppers cash back when they purchase certain grocery products in stores. The catch? Each user has to take a photo of the receipt as proof of purchase of advertised goods, such as a specific brand of pasta or bread. Customers who use the app, which is similar to several other apps including one called Ibotta, receive checks in the mail every time they accumulate $20 of savings.
This article originally appeared on Recode.net.