Once you have created a lesson users you have shared it with will be able to view it through the Xplorer Player.
In order to launch a lesson in the Player you first need to create a room to launch into. The Xplorer Player gives you the option to create a single player or multiplayer room. Single Player rooms are only created in that instance and therefore are not saved when you leave them. You will need to create a new single player room each time. Multiplayer Rooms allow you to send invites to other users. Multiplayer rooms will be saved once created, therefore, they can be left and re-entered at a later date.
The Join Room tab is where all open rooms you have access to are listed. As soon as you create a multiplayer room it will be listed in your list of hosted rooms which you can close or re-enter. Any rooms you have been invited to will be listed in the invites list.
In order to join a room you have been invited to you must have the project downloaded. Invites that appear in red indicate you do not have the required project downloaded. To download the project click the "Download Online Project" button that is located in the bottom left of both the "Create Room" and "Join Room" tabs. From there you can select which project to download.