I've been having some success getting leap motion to google cardboard, but as it isn't officially supported there are a couple of annoying bugs. One of which is when you mount the leap motion on the head, if you keep your hand still and move your head the hand moves in the world space, similar to this problem:
However I'm using javascript and whereas the original post is using Oculus/C++ (i presume) where Leap have a way to fix this. It says instead of using Controller.Frame use LeapServiceProvider.CurrentFrame which applies a transform to compensate, which is not included in the Javascript API.
Does anyone know how to fix this, or at least know anything about the transform so I can create my own?