Many games on the App Store seem to emphasize gaming expertise more than anything else. Either you need to know the genre of the game you're playing, or your fingers just need to be fast enough to win. Look Again! is an interesting contrast to either of those scenarios because it challenges your brain's pattern recognition skills more than anything else. You're given a graphic consisting of two design elements, and it's up to you to figure out which two elements make up the graphic. Like all good puzzlers, things start simple but get increasingly more complicated, even as your brain trains itself to better recognize what's going on.
The presentation's not incredible (the colors are a little weird), but it serves its purpose. There are over 250 levels, full Game Center integration, and the app was recently updated to work on both the iPhone and the iPad. Look Again! is currently available for US$1.99 on the App Store. If you want an iPhone game that runs at a different speed, check it out.