This app was mentioned in 2 comments, with an average of 1.50 upvotes
I do. I've read on here that there is another app, Car Gauge Pro, that works with the ELM devices that is better (you can actually initiate tests). Link to thread discussing it. Supposedly it isn't as intuitive as Torque but offers much more functionality.
Torque will show data live from your sensors, you can set up screens with gauges to view certain sensors ( boost, EGT, etc) or view and clear engine codes. It is very intuitive and dead simple to use.
I recommend buying the smallest ELM adapter you can find. Keep it in the glovebox/armrest and bust it out when needed. You can drive with the short one plugged in to collect live data or speed stats if thats your thing.
I have a Samsung Galaxy Tab 7.7 and an ELM 327 generic adapter that I use with Car Gauge Pro, it's more advanced than Torque and offers more options as far as ABS, Air Bag and body control module support on Ford, Chevy, Dodge and Toyota. I'd recommend if you have a Ford or Toyota especially to use this program, it's complicated to use when compared to Torque but it is better.