xkcd Explainer is a useful Chrome add-on developed by Simon Zou. It falls under the category of Browsers and specifically the subcategory of Add-ons & Tools. This free program aims to provide users with a better understanding of xkcd comics by adding a link to the explain xkcd wiki directly on the xkcd website.

With xkcd Explainer, users can easily access additional information about the comics they are reading. By simply installing the add-on, a link to the explain xkcd wiki will be available on each xkcd comic page. This allows users to dive deeper into the context, references, and explanations behind the comic, enhancing their overall reading experience.

By providing direct access to the explain xkcd wiki, xkcd Explainer saves users the time and effort of manually searching for explanations elsewhere. Whether you're a long-time fan or new to the world of xkcd, this add-on is a valuable tool for gaining a deeper understanding of the clever and often thought-provoking comics created by Randall Munroe.