after connecting to a machine there is no disconnect button on both sites (Only right click to tray Icon).
And there is no Information on the remote site that inform the user that someone is connected to his Maschine.
On the client, you can disconnect by closing the session window with the X button. I don't think an explicit "Disconnect" button is necessary, most remote desktop programs work this way.
As for the server-side, you have already found "Disconnect" in the tray icon menu.
However, you are correct that there is currently no visual indicator that someone is connected to the machine. The only hint you have can at this point is that the "Sharing" submenu from the tray icon is only present if someone is connected. We understand this is a usability issue that will be fixed soon.
Thank you for your feedback