This ASP.NET MVC application uses Twilio to track the effectiveness of different marketing channels by purchasing phone numbers, forwarding incoming calls, and displaying charts showing data about the phone numbers and calls they receive. The application has three main features: searching for available phone numbers, buying phone numbers, and displaying statistics on lead sources. The backend part of the code creates a LeadSource and associates it with a Twilio number, while the frontend uses jQuery to fetch call tracking statistics in JSON from the server and display them in colorful pie charts created with Chart.js.