Thanks for releasing this. I got it working after messing with it a bit.
I am not sure if this is a Google ARcore problem, but it doesn’t seem to track blinking. Because of that, it also seems to float when you do blink, but I was really impressed with how accurate it was.
Additionally, my phone (Xiaomi Mi 8) would have issues once the screen fell asleep.
Otherwise, thanks for releasing this to play with. I can’t find anything Android side that is remotely in this price-range =)