Insurer State Farm's released a free Driver Feedback app that turns your iPhone into a pocket-sized backseat driver. At the end of every journey it critiques your skill at the wheel. Sound fun? It’s all in the spirit of good driving, the company says.

The Driver Feedback app can help identify problem areas, providing drivers of any age with useful tips to help reduce the risk of crashes,” says the press release.

This annoying little app uses the iPhone’s "accelerometer" to help measure things like how much road rage you have or how calm a driver you are. Apparently, it can tell through your acceleration, braking and cornering. Oddly enough, the app doesn’t monitor glares, hand gestures, phone conversations or nodding off while driving. It’s “particularly useful” for parents teaching their teens good driving habits, State Farm says. Parents can now force their children to turn on this Big Brother-type app while driving. When the teen completes a trip, the app can send a text or e-mail with a score. It also includes a map that illustrates where “potentially dangerous activities occurred.” State Farm says it doesn't collect the information gathered. Somehow, that's not particularly reassuring in light of all the news lately about how Apple and Google were  collecting smartphone data. This app could be useful in determining insurance rates. Just saying. I think I’ll pass on the opportunity for a insurance company to rate my driving habits, if only because I never want to be tempted to throw my iPhone out the window.