Strips Twitter of all identity information (names, photos)... and leaves just the content. In other words, it allows you to run a blind taste test on Twitter.
The easiest way to install the extension is via the Chrome Store
https://chrome.google.com/webstore/detail/blind-twitter/kpepkofhiialmklmmghnljndeejjaokb
To understand how you can modify the extension see, for example, this guide
https://blog.lateral.io/2016/04/create-chrome-extension-modify-websites-html-css/