Homestuck Companion is an extension for your desktop or mobile browser, which displays Andrew Hussie's commentary for Homestuck, complete commentary for Problem Sleuth and enables keyboard navigation for all adventures on the site as well as Homestuck^2.
Afterwards, navigate to a valid Homestuck.com page like https://www.homestuck.com/story/1. You will be able to see the commentary for pages that have it
Keyboard controls: the Left and Right Arrow Keys allow you to move back and forward in the story. The right Ctrl key is used to open or close Pesterlogs and logs of any kind.