Call progress events are a useful tool for tracking the state of phone calls made with the Twilio Voice API. By setting up an Express server in Node.js to receive HTTP requests from Twilio whenever the status of a phone call changes, developers can build a dashboard or application to monitor and manage these calls in real-time. This is achieved by installing the necessary dependencies, including the Twilio Node module, Express, and BodyParser middleware, and then setting up routes for handling incoming requests and generating TwiML responses. To test this functionality, ngrok can be used to expose the server to the internet, allowing Twilio to send HTTP requests to the `/events` route when a call's state changes. The code provided demonstrates how to make outgoing calls using the Twilio REST API, specify which events to listen for, and authenticate with Twilio. With this setup, developers can build a range of applications, from simple dashboards to more complex systems that utilize real-time data from call progress events.