We develop for smartphones/cardboard and for VR headsets
(and of course for mobiles, tablets, computers, VR installations?)

Web VR: Explore Virtual Reality with a Simple Smartphone
Cardboard is a simple system, which has existed since the 17th century (yes, really!), and is called "stereoscope" in French. Cardboard is simply a smartphone inside a stereoscope. It's an inexpensive virtual reality system that's easy to use and deploy.

VR headsets
The standalone headset system is different: the optics, gyroscope, and screens are all part of the VR headset, and the whole thing provides a much more immersive image and experience than with Cardboard. Headset rental is available for your events.