Very Handy
Ive only used this app to track my flight, not to use it as a controller. It works great thus far. No plug-in is needed therefore it should work on Mac, Windows and Linux. (I use it on OS X).
I have two enhancement suggestions. One, let it work in landscape mode as well as portrait (for flight tracking) and two, have a option to turn on a "trail line" that shows the path your aircraft has travelled.
After reading the descriptions of a number of the other X-Plane flight tracking apps I am satisfied with this one. Again, no plug is needed. It uses the already built into iPhone/iPad control feature.
Rod T. about
X-Mapper Pro (for X-Plane Desktop)