Suggestions

Good work:

below options will make it a great tool 
1. Keyboard (in the toolbox)
2. Hands up (Notify attention)
3. Share Screen
4. Share URL (i.e. play a youtube video)
5.  Add participants (invite others by sending a link)
6. Everybody follows me

I'm not sure how hard it is to implement these options but will make it a great tool.
Please, have a look at https://meet.jit.si 

Thanks   