Also lets download the extra controllers Requires Unity 4.6.3 or higher.
Cardboard Controls+ is all you need to develop the best Cardboard games in Unity.
These scripts enhance Google’s official Cardboard SDK for Unity with event-driven improvements for discrete magnet control,
orientation tilting, and gaze raycasting. Stop limiting your creative options! Usage
Today I was having a problem getting a first person control to work in Unity for Google Cardboard. I had done it once but could not remember how to do it again. The problem I was having was that once the controller was attached to head i has just falling through the terrain. I attached the controller to the camera (but not the head) and this would solve the problem of falling through the terrain, but the head was not attached to the controller so movement was set in the start and would not change based on head movement.
My solution to the problem, once you have added a first person control delete its camera. Put it under CardboardMain and all cameras under the first person control. Add a component to the First Person Control. This component should be the CardBoard Head (script). Next uncheck the Track Position button under the Head (script) you just added, and the Mouse Look (script) also under First Person Control. Finally delete the old Head object in the Hierarchy.
Hope this can save some time with anyone else with this problem,