A developer, Kevin Whinnery, created an application that enables real-time collaboration between coders using node.js on the server, Twilio Client for voice communication, socket.io, Express, and Ace code editor. The client-side application allows two developers to share their code changes in real-time while voice chatting with each other. The server-side application handles HTTP requests, socket communication, and generates a capability token for Twilio's soft phone, enabling voice chat and presence events. The application uses socket.io to propagate changes to the text editor and manage presence and voice chat via Twilio Client.