If you're not familiar with the Slender Man mythos, you should definitely look it up, for an Internet-created thing, it's surprisingly well thought out and interesting. And it makes for a scary Android mobile game.
SlenderMan for Android is a lot like the game Slender on PC. You wander around the woods looking for notes, and when you least expect it, the Slender Man will pop up and scare the bejeezus out of you. The object of the game is to collect all eight notes without ever looking at the Man. It's a terrifying experience.
That is, if you're playing the real version of the game. This app includes a 2-D version and a 3-D version. The 2-D is so bad I won't even talk about it. Do not bother playing that one.
The 3-D version, though, is great, even if the world you have to explore is small compared to its PC counterpart. It's got pretty standard first person touch controls, and since precision is not necessary, they don't ever get in the way.
SlenderMan for Android is pretty much what it needs to be, but there is room for improvement. It would benefit from having a bigger world to explore, for one. As it stands now, the game is creepy enough that I can still recommend it. I yelled loudly the first time I saw the Man – and I bet you will, too.