A demo project showing how to create Google Cardboard virtual reality experiences with iOS and SceneKit.
https://www.google.com/get/cardboard/
Even supports the magnetic trigger using a delegate protocol TCCardboardMagneticSensorDelegate. See below.
The project uses two custom classes that give you basic VR support for iOS (TCCardboardCameraNode and TCCardboardMagneticSensor).
Use this class to draw two SCNScenes on the view, one for the left eye and one for the right. Adding a TCCardboardCameraNode to TCCardboardViewController will assign each camera to a SCNScene. This view controller will handle the Auto Layout constraints for you.
Before creating a TCCardboardCameraNode, you will have to create a mirror image of two scenes. This project does this in the storyboard. Create the TCCardboardCameraNode and assign it's leftCameraNode to the left scene's pointOfView and the rightCameraNode to the right scene's pointOfView. This is now your camera that will handle all head tracking motion for you.
Google Cardboard has a magnetic trigger on the left side. The ability to use this isn't unique to Android devices, as you just need to detect the disruption to the magnetic field around the device's compass. That is exatly what TCCardboardMagneticSensor handles for you. Simply inherit the TCCardboardMagneticSensorDelegate and create the method onCardboardTrigger, and you have yourself a basic input for your applicaiton.