Was fine at first, simple sudoku app. I guess it updated or something, because tonight- start a puzzle, ads. Finish a puzzle, ads. Watch the ad after a puzzle, gives you a "prize" with no X option and a "collect" button that brings you to- you guessed it, an ad. Ads are a necessary evil so developers can make money, I understand. I get it. But there becomes a point when it's overbearing and you lose users.