Cardboard puts virtual reality on your iPhone. The Google Cardboard app helps you set up a Cardboard viewer and includes a few experiences to get you started.
To fully enjoy this app you'll need a Cardboard viewer. Learn more and get your own Cardboard viewer at http://g.co/cardboard.
Do not use this app while driving, walking, or otherwise by being distracted or disoriented from real world situations that prevent you from obeying traffic or safety laws.