Since I can't use the app without signing in, you need to place the sign in links more prominently. When I click on a chat room, it says "Anonymous: Sign in to send messages". Please make that a link so that I can click and sign in right away, not look for the sign in links on my own.

It sounds trivial, but little annoyances like these will keep people from trying the app.

You also need to seed the chatrooms with some users and conversation. I don't see anyone in any room.