The Spring MVC framework is being used to build a web application that can send SMS and make phone calls using the Twilio REST API. The application starts by setting up an environment with Java Development Kit 1.8 or later and Maven 3.0 installed, and then clones a GitHub repository containing the initial code for a Spring MVC application. A controller is created to handle incoming HTTP requests and return the appropriate view. The application uses request parameters to determine whether to send a text message or make a call. The Twilio REST API is used to authenticate with Twilio and send SMS messages and make phone calls. The application also includes logic to handle different modes, such as sending texts or making calls, using request parameters. Finally, the view is modified to use the model attributes added in the controller to display the mode and number being sent.