I have an android head, it came with the Torque app, it can monitor boost, speed, charging etc. too much information!
On a long trip my engine light came on, I just get Torque to check the fault codes and it clears them too - its not as deep a dive as VCDS, suspect it may not clear every code it comes across, but handy to have on the road.
Despite the head unit being canbus compatible, for some reason torque still needs bluetooth obd reader.
I was having a bit of bother with battery drain, need to check again, unsure if that was just the head unit or also the bluetooth still running with the engine off.