I live in New York City, therefore I don’t own a car. But once upon a time I zipped up and down the east coast, and I’ve met my fair share of lovely state troopers. I don’t think they were pulling me over to chat about my bumper stickers. There was one incident in particular that I got very testy with a brutish man in khaki– I should have kept my mouth shut. This was before the iPhone was even invented, but it would have been great to have some evidence that I wasn’t going that fast.

According to TicketDefender, more than 100,000 drivers per day receive speeding tickets. Some experts estimate that 10-20% of all radar-backed speeding tickets are issued in error; and in the case of radar that is operated from a moving police vehicle the number of inaccurate tickets may be as high as 30%. Let’s do the math: for every 100,000 drivers getting a speeding ticket, up to 30,000 people could receive a ticket in error. If you’re one of those statistics with a lead foot, there’s an app for that.

For ease of use, TicketDefender gets an A+. Download the app – at $1.99 it’s potentially much cheaper than an actual ticket. Name your car, type in your license plate, and turn on your iPhone as it rides shotgun. As you cruise down the highway, blasting your old-skool-road-trip mix and stuffing Cheetos in your face as you maneuver with one knee, the speed, time of day, and GPS location is automatically recorded with TicketDefender. If you get pulled over, you click the ‘press when ticketed’ button (while simultaneously reaching for the glove compartment for your hand gun, err, vehicle registration).

The app generates reports more thorough than your monthly phone bill. Reports include the vehicle’s make and model, license number, time and date of the recorded speed. The Speed Report shows the recorded speed every 3-5 seconds and the location in latitude and longitude. The Map Report shows the street view of all recorded speeds. If these reports show the speed indicated on your ticket is different from the speed shown on the TicketDefender reports, then you have a valid “not guilty” argument.

But good luck pulling out your iPhone in front of a judge – he may just take the side of the state trooper over your gadget. So always remember to dress smart and act nice when confronted by The Law.