Recently, I got an app called Super 7. This is a game where you drag number disks toward each other to create the number 7, without going over. There are also negative number disks, disks that change the number from positive to negative, or vice versa, disks that decrease the number of the other disk, and disks that multiply or divide the number of the other disk. Think it's easy? Trust me, it's not.
Personally, I think Super 7 is a super fun, exciting, and challenging game. It's simple, and yet it's complex in it's own special way. It's such an easy game to pick up and play, but so hard to put down! You'll be trying to get the high score all night!
I highly recommend this game, and also, check out No Monkeys other apps!