Eyeware Beam - Turn your phone into an eye & head tracker!
Unity - The multiplatform game creation tools for everyone.
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
Godot Engine - Feature-packed 2D and 3D open source game engine.
FaceTrackNoIR - FaceTrackNoIR is only available for Windows-based PC's (sorry, we have to start somewhere) and...
Blender - Blender is the open source, cross platform suite of tools for 3D creation.