A Ruby-based 1:1 video chat application is built using Twilio WebRTC Go, allowing two participants to engage in free one-on-one video conversations. The application consists of a Sinatra server and a JavaScript client-side application that enables users to connect to a video room and join or leave the call. The application uses ngrok to create a temporary public URL for the video chat, allowing users to access it from any device. The code includes functions for handling user connections, disconnections, and track subscriptions/unsubscribes, as well as displaying video feeds and usernames in real-time.