Similar to the bookmarklet, this is a Chrome extension which adds auto-scrolling functionality on any web page.

Once enabled, a slider appears at the bottom of the page. The scolling speed can be adjusted by using this slider. A button 'Stop Auto-Scroll' also appears at the top of the page, to stop the auto-scrolling altogether.

While the extension is active on the page, click anywhere on the page to pause the auto-scroll and click again to resume.