iPhone and iPad app to run in parallel with your X-Plane simulator (it supports both X-Plane 11 and X-Plane 12).
Make sure your device is connected to the same network as the machine where X-Plane is running and the app will automatically find it and will link to it. Once linked, your flight data will start arriving to the app and therefore displayed in the map. On the Menu you can see flight information like your speeds and altitudes. You can also connect and download your current flight plan from Simbrief to get some extra flight information like arrival, destination, flight time, distance traveled, etc.
Enjoy!