What is the difference between the main app and the companion app?

The Main App is the app that loads the video which will be watched by your family member, friend, or resident who has dementia. It must be loaded on a phone that will be placed inside the VR headset.
The Companion App allows you to watch the same video they are watching from a second device and share the experience with them. It is loaded on a second device which is not placed inside the VR headset (it can be another phone or tablet).