G-Meet Auto Join от Prakhar Gurunani

Who the hell loves attending 8 A.M classes ? Someone else can do this job more efficiently.

Just save the meeting specifics (URL, time, duration...). The extension enters the meeting automatically, with audio and video turned off. It departs the meeting and closes the tab when the user-specified duration is achieved. Because this is a reoccurring event, the user will not have to save the meeting information every week.

Note - The extension will not work if the browser is closed (basically true for all extensions). Atleast one browser window needs to remain open for the extension to work correctly.