ForeFlight can be connected to Flight Simulator programs running on desktop/laptop computers, or even full-size simulators.  Depending on the simulator, the connection can either be via WiFi (using the "UDP" protocol) or by a wired connection to the iPad.

Simulators supported by ForeFlight are:

 1: AeroFly FS 2

 2: ELITE

 3: Frasca

 4: Infinite Flight

 5: Microsoft Flight Simulator 2004 and FSX 

 6: Prepar3D

 7: RedBird

 8: X-Plane