Admittedly, I didn't read the source code, but looks like this would use the gyroscope API (edit: it does)? Probably wouldn't use this profusely, but it seems like a nice addition for things like credit card inerfaces. Pretty neat!
Thanks! Indeed it does use the gyroscope. Unfortunately (as always on the web) the implementation apparently differs a lot per device so I'm now gathering test devices to make it respond the same on iOS and Android.