Twilio Functions and Assets provide a platform for building custom web applications that can access Twilio APIs, allowing developers to create single-page apps hosted on the Twilio Runtime platform. By utilizing functions and assets, developers can bypass CORS restrictions and build applications that can be accessed from anywhere in the world. The example code demonstrates how to set up a serverless project using the Twilio CLI and Serverless Toolkit, creating a custom web app with a backend hosted on Twilio. The frontend uses React with Webpack and Babel for building, bundling, and minimizing the codebase. The application consists of three components: a top-level component that handles user input and form submission, a LookupInput component that binds to form inputs, and a LookupResults component that displays the lookup results. The example showcases how to deploy the app to Twilio using the Serverless Toolkit and provides a starting point for building more apps with Twilio Functions and Assets.