In this series of videos Prof. Patterson develops a web application version of Reversi (aka Othello) using HTML, CSS, Javascript and jQuery. The infrastructure is managed by Github and Heroku. By watching these videos and following along on a computer, you should be able to build the same application on your own. This is the third of sub-sequence of tutorials in the series that focuses on building a lobby interaction for connecting players to each other. This video finishes setting up the environment and making sure that each client in the lobby gets notifications when people come and go. This video is used in courses taught by Prof. Donald J Patterson (@djp3) at UC Irvine and Westmont College.