In golf, comparisons are key. The free Ubersense app lets you record a swing and then compare the results side-by-side to a pro golfer. There are 50 pro videos showing how to play the game, plus another 40 lessons on key fundamentals like fixing a slice and extending your spine. Of course, you'll need a buddy along to set up the phone and record. For now, the app only works on the iPad and iPhone (or iPod Touch); there's no Android version. [Free; ubersense.com]