Have some kind of live activity indicator

[jkomoros]

Ideally it would show distinctly colored (anonymous) dots for each person, which would show up in a summary view in th eheader for the entire presentation, but also show up as they jump around the cards (seeing the movement and others helps with virality)

[jkomoros]

https://firebase.google.com/docs/firestore/solutions/presence

[jkomoros]

• [ ] Ensure updateUserInfo() is called on sign in, and potentially on a timer while the tab is open to implement poor person's "live activity".
• [ ] Have a cloud function that periodically fetches the live_user_count by fetching the size of userInfos that have lastSeen in the last, say, 90 seconds (slightly longer than the periodic refresh interval of updateUserInfo on client to ensure that we don't ping pong whether a given user is active), and upates that on counts object. Also do that for stars, and reads

[jkomoros]

Consider using Google Cloud Scheduler to schedule the updates