TrackIR - TrackIR adds depth to the PC gaming experience by enabling players to take control of the in-game view.
Eyeware Beam - Turn your phone into an eye & head tracker!
Oculus Medium - Sculpt, model and paint in virtual reality on a 3D canvas.
FaceTrackNoIR - FaceTrackNoIR is only available for Windows-based PC's (sorry, we have to start somewhere) and...
Tilt Brush - Paint in spaces around you with Virtual Reality
VSeeFace - VSeeFace is a free, highly configurable face and hand tracking VRM and VSFAvatar avatar puppeteering program for virtual youtubers with a focus on robust tracking and high image quality