Just before I hit the sack having some fun on my phone
This is Rullo. Pretty fun app. Deselect all the red numbers such that the sum of all the numbers in a single column or row is equal to the corresponding number on the side of the square. FUN!
Better go to sleep and not play again. That was too much fun.
btw here is the app link if you are interested in mathematical fun https://play.google.com/store/apps/details?id=air.com.akkad.rullo&hl=en