Cannot find any fault with it. I plugged it into my car, used my iPhone to attach to the Wi-Fi it emits, and then loaded up a free app I downloaded. Showed all the current real time information, didn't have any faults to report etc. Works as planned. Took less than1 minute to get working. I also then tried with Android, worked just the same using a different app. Worth the $ since my local garage charges $90 for a 'diagnostic test' when the check engine light is on.
I just got this handy little guy a couple days ago and so far so good. I have a 2008 Grand Prix that's having a gas cap issue which is ALWAYS triggering the check engine light. I can ensure the cap is on but the light won't go off. Because of that, I'm never 100% sure that the gas cap is the issue so I always have to take it in and get the garage to check it out just to have them say it was the gas cap and clear the code. Saves me a ton of trips to the garage and now I can see for myself what code is in fact being set off AND I can clear it myself. There's also a bunch apps compatible with this device for iOS which is nice to give you the choice. I personally use OBD Car Doctor and it works really well.