Opentrack smartphone head tracking

If you are interested in, here is tutorial: Short preview how work smartphone HeadTracking on Opentrack with Elite Dangerous. This should work on every game with support of Freetrack or TrackIR protocol. Homemade and FREE. Solution looks funny, but works perfectly. You can use it in games such Elite Dangerous, Star Citizen, Arma, War Thunder, Assetto Corsa and many others.