Add-on breaks normal hyperlinks within the page. Like annotations in html-books, which add smth like "#66" at the end of adress and you should jump somewhere. With add-on turned on you just jump on top of the page. Checked by turning off and turning on this add-on. Sad, add-on is useful.

Cool, but the title of the extension is misleading. It's not an highlighting tool.

Great. Helped me a lot with saving my place in long docs