I have thought about getting a GS-911 for a few years now, but have been wary because of cost, and concern if I would be able to use it with my iPhone. There is a lot out there about the GS-911 and the Motoscan App, none of which seemed straightforward to me as a non-techie. I thought I should record for anyone in a similar situation, I bought one and set it up following the instructions and then used my iPhone to calibrate a new fuel strip today. It took a couple of attempts, but the device is easy to set up and worked well, even if I am not sure how!