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A guy in a car forum I belong to has that and loves it. It does a lot more than just read/clear CEL codes.
 
I have the rev app and love it. You also have to buy a cable to connect to data port on the car for it to work. I am a mechanic and use real scan tools at work but I still get alot of use out of the app. Plus the cool factor when you pull out your phone to help you buddy fix his car is great.
 
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