React Fiber Visualizer is a free Chrome add-on developed by typelulu. It falls under the category of Browsers and is specifically categorized as an Add-on & Tools.

This add-on allows developers to visualize the Fiber data structure in React applications. By installing React Fiber Visualizer, a new "Fiber" tab appears in the Chrome DevTools panel. Clicking the "Refresh" button in the Fiber tab displays the Fiber data structure.

It is important to note that React Developer Tools is a dependency for React Fiber Visualizer. Therefore, make sure you have React Developer Tools installed. Additionally, this add-on has been tested with and its compatibility with other versions of React applications may vary.