There are more than a few Adventure Time games out there, including the as of yet unreleased 3DS game (which is shaping up pretty nicely).
But of the iOS games out there, this one is actually fun and riffs on the delightfully silly humor that makes the show so great.
SJumping Finn Turbo is a flight game, in the sense that your goal is to gain as much mileage out of one flight as possible. So basically Jumping Finn Turbo combines the awesomeness that is Flight of the Hamsters with the silliness that is its Adventure Time icing.
As you gain points with each round, you can spend the in-game currency on upgrades to Jake's kick in Finn's butt that sends him flying, or purchase Marceline who furthers your flight with the whack of her guitar against your cushiony skull (there's a lot of blonde hair under that hat).