Go to the project's root folder and compile the signaling server using the following command:

rebar clean
rebar get-deps
rebar compile

If you're under the Linux box, start the signaling server using the following command:

erl -pa deps/*/ebin apps/*/ebin -sasl errlog_type error -s rtcserver_app

If you're using the Windows box, use the following command to start the signaling server:

erl -pa deps/cowboy/ebin deps/cowlib/ebin deps/gproc/ebin deps/jsonerl/ebin deps/ranch/ebin apps/rtcserver/ebin -sasl errlog_type error -s rtcserver_app

Now, point your web browser to the domain or IP address where the application is accessible. You should see two buttons and a link (URL). In the following screenshot, you can see Chrome and the main page of the application:

Open the link in another web browser or any other computer; you should see a similar page there. I used Firefox...