We should tell that the webapp can be used without any headset on mobiles

[ric-bianchi]

On mobiles, users can "navigate" the 360degrees world without any headset by moving and tilting the phone. We should write that down into a piece of documentation.

Also, we should write advice on how to use the app with different headsets:

• Oculus Go
• Google Cardboard ( ==> and here we should warn people that a google cardboard case must fit their phone perfectly, otherwise, the 3D effect vanishes: you see two images if the phone is larger than the case, or you see the phone's screen's edges if it is smaller)