This is an excellent alternative to spending $200+ for TrackIR or Tobii. It uses your Ipad or Iphone to perform basic head tracking. Device must be on the same network to operate correctly (this stumped me for a while). Instructions to download Opentrack (pc download) and Head Tracker ($2 Iphone app) here: Head Tracking Quick-Start – JBC Head Tracker
Using the Accela Filter and adjusting deadzones and smoothing seemed to be the key to make it feel really intuitive. It takes a lot of tweaking to get right, but once you do, it is almost flawless.
I’m using an Ipad 11 pro for my Head Tracker app. Only recognizable flaw is camera lag (less than .25sec).
Edit: To add to this, there are options to use webcams and android phones, although I haven’t tried this myself yet. https://www.reddit.com/r/StarWarsSquadrons/comments/kbpq2s/use_opentrack_aitrack_to_get_headtracking_with/