My Cardboard does not have a stereoscopic effect on the device. However, he works in an editor.
This is how it looks in the editor. http://i.stack.imgur.com/sN14x.png
This is how the device looks http://i.stack.imgur.com/7XpeD.png
He worked with Unity 4.6.
I tried it on multiple devices.
Config: -Unity 5.0.0f4 Personal - Cardboard SDK v0.4.5 - Provided on Galaxy Note 4 and Nexus 10
. ( ..). , , StereoController "Direct Render" false.