Platformers are a tough genre to pull off on a touchscreen. There are a few solid core platformers out there for iOS (Mikey Shorts is probably my favorite), but in general, the lack of tactile buttons and relative shortage of screen space make really precise, strong 2D platforming games hard to do on Apple's devices. Cling, however, is a platformer put together by a team called First5 Games, and it slickly dodges the whole problem of imprecise virtual buttons by using a virtual joystick instead.
The hero of the game is a little toy creature similar to the old "wall-crawler" rubber toys popular a while back, where you could stick them on a surface and they'd slowly "climb" down it. Edgar is this creature's name, and he can get around in the game by grabbing on to different pegs, and using those to move through the game's various levels. There are a few different varieties of pegs (some attract, some repel), but the main mechanic here is that if you're not near a peg, you can't control your little guy, which means that some of the levels have to be approached very carefully. It's a really interesting concept, and it turns the idea of a platformer (a game where you jump from platform to platform) upside down. "Jumping" in this game means vaulting yourself from a series of pegs, and if you go off at the wrong speed or angle, it's game over, time to restart the level.
In that sense, Cling is a really interesting experiment, and it's well worth a try, especially if you're a fan of platformers, for the price of just 99 cents. The game just got an update recently and unfortunately it seems to have introduced some bugs. But that issue should be fixed soon, and even until then, it shouldn't prevent you from giving this one a look.