Dishonored: Rat Assassin full review
If you also game on console and/or PC, Dishonored is the game you need to be playing right now. This stealth/assassination game wouldn't really work on the limited controls of touchscreen, so rather than put out an embarrassingly hobbled version (see Mass Effect: Infiltrator) the tie-in mobile game does for a different approach entirely.
So, it's Fruit Ninja with rats. Shamelessly so, to be honest, but hey, it's free, it's a reliable distraction and it does a good job of evoking Dishonored's grimy, rodent-infested world while still being as silly as a game about swiping desperately at objects hurled up the screen needs to be.