Good, very useful idea, sadly not well developped, for example on pages with expandable content, markings are not restored (the "page can change" function does not help).

Fonctionne pas !

>>> NO ACTUAL SCREENSHOTS OF EXAMPLE MARKUP ON PAGES! <<<

Crazy resource consumption.
If you use many tabs, please DO NOT INSTALL, or your Firefox will freeze and it will be really hard to remove the extension.

@Developers: no, my computer is not slow (like you replied to another user). You should learn how to optimize your code instead of blaming users that complain about it.