I use a BAFX Products - Bluetooth OBD2 scan tool that I bought on Amazon for 23.99. It's a wireless Bluetooth scan tool. Not very high end at all. I connect it up to Torque Pro (4.95 from Appstore) on my phone and tablet. I can view just about every sensor the car or truck has and get full readouts while driving in the car, including digital gauges. So far I have not found much that I haven't been able to do with it; read & clear codes, diagnose recent CAT issues with the truck, etc. Again, it's not a high end OBD2 tool but it works pretty well for so cheap!