Hi,
Currently, there is a start/pause button in the upper left of the interface, next to the Live logo. I couldn’t find where to end a session (there is no “stop” or “finish” button), and eventually found it on the config page, “Mark session as completed”. I think it would be more intuitive to (also?) have a button in the same place as the start/pause buttons to end a session, and mark it as completed.
Cheers
Oli