RiftCat out of Poland is showing off VRidge which enables users to Play any PC VR game on a $1 Google Cardboard or on any Smartphone based VR headset. It works over Wi-Fi, by USB cable. It works with for example Steam VR, this is a cheap alternative to HTC Vive and Oculus Rift. They encode and decode the video game and VR content from the PC over to the Phone. They can even suggest a DIY infrared tracker, leapmotion, and other to also support head-tracking.