Some Electronic Flight Bag (EFB) apps such as FltPln and ForeFlight can also connect to most of the popular flight sim apps like Xplane, MS FSX and FS Flight Simulator 2020.
FlightPlane has some great instructions for connecting to flight sims using a number of different approaches. The easiest option I’ve found so far is to download the Flight Events app from https://events.flighttracker.tech/ . Press the Join button top right and follow the instructions.
Enable the ‘Broadcast data to local network’ option. Initially ForeFlight didn’t show the Flight Events panel under ‘More… Devices’ until I entered the current ip address of my iPad on my network in Flight Events (instead of the default broadcast option) :
and the Flight Events appeared in the Devices panel here:
Click ‘Flight Events’, enable, and then ForeFlight is sync’d with your sim.