Live video broadcast and AppShare are now enabled by default for the Express client
Prior to this update, the capabilities to broadcast live video and AppShare data to other clients in a Cornerstone Classroom session were added to the Express client. However, these features were in a 'Beta' phase and were disabled by default. To enable them, organizations had to submit a request to their Account Manager.
Over the past few updates, these capabilities have been enhanced and tuned for improved performance.
Share live video
When the leader or co-presenter grants camera privileges to a participant, the participant
in the Express client can broadcast live video in a session by clicking the camera ()
icon.

For more details, refer to the Use videos topic in Cornerstone Classroom help.
Perform AppShare
Participants using the Express client can now share applications with other attendees in a session using AppShare. When the leader or co-presenter requests a participant to share their application, the participant sees a message in their Express client. The participant can click Yes to start AppShare.

Once you enter the AppShare mode, the sidebar in the Express client displays additional AppShare-related icons.

For more details, refer to the Share an application topic in Cornerstone Classroom help.