I have an OBD2 interface that's bluetooth. Anyone found a great app for android that understands Jaguar very well?

 

Guessing, no experience with BT OBD-II except in a couple of my previous cars, but I think you'll find that you'll only have access to powertrain codes, and none of the other modules. it may find Jaguar-specific codes, but most likely only in the powertrain, which is the basic universal OBD-II spec. Items that are "manufacturer discretion" will probably not be available, nor will data from chassis or body modules.

 

Torque Pro
However. as wfooshe points out, it will only give powertrain DTC's and readings etc; still very worth having!
If you want Jaguar-specific, then the ICarsoft LR V.1 works okay for me at a reasonable price?
If you do go down that route, do not update the firmware, as doing so loses some of its functionality

 

Nothing out there eliminates a certain amount of guess