This app was mentioned in 2 comments, with an average of 2.00 upvotes
Givling. It is a trivia game and you can play for free everyday. They give out cash prizes daily. They also put you in a queue for the chance to get student loans forgiven (but you don't have to have student loans to play). https://itunes.apple.com/us/app/givling/id982442237?mt=8 and https://play.google.com/store/apps/details?id=spec.com.givling&hl=en You can use code SR277352 to get an extra free coin. Anyone can use this code.
Maybe it was Givling? https://play.google.com/store/apps/details?id=spec.com.givling