PixelPop

A fast, fun game where you double-tap clusters of 2 or more same-colored blocks to make them disappear. The bigger clusters you get, the more points you'll score, and if you wind up with fewer than 25 blocks, you can move onto the next level. Watch out, though, because at level 3 and level 5, the difficulty increases!

Consider upgrading to the Pro version for $1.29, which allows you to play the game without ads. The saved screen real-estate allows for a bigger game display.