Fun to use initially, besides the demos, the app seems to function as a launcher. I couldnt figure out how to access the camera to make my own 3d vr panos. Later, I found the spherical camera in Google Streetview app, that wasnt clear to me at first.
Google cardboard is cheap , but the assembly isnt that clear, they mustve hired the people from ikea to create the assembly instructions.
This type of 3d is more immersive than looking at stereograms, but the viewer is practically identical, still fun to look at.
Grunt head about Google Cardboard