Wallhaven Extender is a free Chrome extension developed by Richard Moss that adds convenient features to the popular wallpaper website, Wallhaven.cc. With this extension, users can easily download and view wallpapers in a slideshow format.

One of the main features of Wallhaven Extender is the addition of "Download" and "Popout" links onto all thumbnails across the site. This allows users to quickly download wallpapers or view them in a fullscreen pop-up slideshow. The slideshow feature includes all the wallpapers available on the page, excluding the forum section, and will automatically load new content as you scroll through.

The slideshow can be controlled using keyboard arrows, making navigation a breeze. The left and right arrows allow you to scroll through the slideshow, while the down arrow allows you to download the current image. To close the slideshow, simply press the up arrow. Additionally, pressing "F" will un/favorite the current image.

Wallhaven Extender also adds download links to the sidebar on the wallpaper information pages, providing users with easy access to download their favorite wallpapers.

Overall, Wallhaven Extender is a useful extension for anyone who frequently uses Wallhaven.cc for wallpapers. It enhances the browsing experience by adding convenient download and slideshow features. You can find the code for this extension on GitHub for more information and updates.