This tool is a bridge between web application at https://subtitles-robot.com and locally installed VLC player.
Usage: select path to movie file and enter password to connect to web application, then click 'connect' button. When the connection is ready (a message 'waiting for incoming connection' is displayed), just start movie playback and this tool will report current position of the movie to the web application.
This way the subtitles in the web application will be synchronized with the movie.