Having just received an iPad 2 for my birthday (2 weeks ago), I am addicted to several game apps but none more than JETPACK JOYRIDE!
This is an awesome app that became available on April 1st and is super fun and addicting! It is only .99¢ and I recommend getting the counterfeit coin upgrade for another .99¢ (this doubles every coin received in the game). It is super useful, as it helps you purchase all those diferrent jetpacks, clothes, vehicle upgrades much faster.
I am currently on my second cycle through the game and have one more achivement to go (i am 29/30); the Angry Wings achievment that requires you to get the profit bird vehicle twice in one game.
I cannot wait for any future DLC for this game, i rate it a solid 5 stars :-D