Twilio CodeExchange is a searchable directory of customizable code samples that developers can use to build Twilio apps. It allows users to browse existing templates or search for specific use cases, and provides download instructions for the chosen template. The platform currently offers 12 sample apps in five languages, with plans to add more regularly based on user requests. Users can download the code samples as ZIP files or view them on GitHub, and customize the code to fit their specific needs by following the instructions in the project's README.md file. Twilio experts have vetted the code samples to ensure they are reliable and easy to use.