Most of the OBD-II data that's available in TrackAddict at the present time is via standardized SAE / Mode 01 PID's, which is the norm for most general OBD apps. There's a list of what's possible on
Wikipedia if you're interested, and what will actually be available in most of these apps will be a subset of that, based on which PIDs the app supports and which one the manufacturer has chosen to actually implement in this way for your particular vehicle. Unfortunately, TrackAddict is pretty much limited to that right now.
Although there's a plethora of additional and very useful data that the engine computer and other systems have, that is proprietary to each manufacturer, so it takes reverse engineering for that specific make/model/controller. In the future, I do expect that we'll be able to offer a huge number of these data channels for the vehicles that we support via the HP Tuners VCM Scanner, but we can't yet announce any details or an ETA on that.
Another option would be to offer the ability for users to define their own parameters, assuming they know the correct PID / address and data format information... That's something that some OBD apps do that I've been wanting as well. It definitely wont make it into the v4.0 release (users should see that in a couple days), but it is at least on my list to explore for future updates...