iPing
Leave it to a club manufacturer known for its personal customization to figure out how an app can help your putting game. iPing (Free;) is a new app for the iPhone and iPod touch that identifies your stroke type, analyzes your impact angle, and measures your tempo, creating a "Putting Handicap" that gets lower as you become more consistent. Simply pick up a Ping cradle ($30) for your iPhone 4 or iPod touch 4G, snap it onto your putter, and get to work.