The Inetmafia.ru Lobby Monitor is a Chrome add-on developed by Yevgen Sh. Inc. It is a useful tool for users of the inetmafia.ru website, allowing them to view a list of tables and players in a pop-up window without the need for authentication. The add-on also provides the option to subscribe to notifications for the start and end of games. In addition, it displays the number of occupied tables in the background, providing real-time updates. With the Inetmafia.ru Lobby Monitor, users can stay informed and keep track of the ongoing games and players on the inetmafia.ru website.