A while ago, I wrote about an ingenious little app named Bloop, which was a multiplayer game for one iPad, where up to four different players had to tap on little colored squares on the screen to see who could clear them off fastest. The creator of that app, Rusty Moyher, was later approached by another team of developers named Game Oven, who were then working on this app, called Bam Fu. Bam Fu is similar to Bloop, in that it too is a multiplayer game for one iOS device, and you need to hit certain colored shapes on the screen.
But Bam Fu's one big innovation is that it adds a little more complexity to the game. Instead of just clearing your own color from the board, the various "stones" on the iPad's screen instead switch to the next color in the sequence when you touch them. So you might flip them one way, your opponent may flip them back, and then so on. Or you might play a little mind game, and try flipping them to your opponent's color, so that one false hit could send them back to yours. The addition of that extra mechanic makes things even more chaotic, as you have to not only hit your own color, but try to send other colors back to yours.
Of course, the one drawback here is that Bam Fu isn't really a solo game -- it's meant to be played with others. But if you have some willing participants (in your family or at your next party), it's a great time, available right now for just 99 cents. Moyher originally put together Bloop as a little experiment on iOS, but the creators of Bam Fu have taken his idea and run right ahead with it.