Xplorer lessons can be played in single player or mutliplayer. Multiplayer allows you to create a room and invite users in a presentor/observer style where one user has control over changing the state of the model while other users watch and follow along.
In order to play a lesson in multiplayer you will first need to use the Editor Portal to upload your project to the server. Once your project is uploaded to the server continue with the following steps.
In Xplorer Player after logging in:
When creating a multiplayer room like this all invited users will recieve an email and in-app notification
You can re-join a previously created room through the join tab under the "Hosted Rooms" Section.