It's really trying but doesn't actually work. The extension grabs the information that it thinks is relevant from the open site and arranges it into what looks like a citation, but the amount of errors mean that I'm constantly fixing and second-guessing the provided citation, so it really would be quicker to do it manually or to use a citing site.

For example, I just tried to cite an article directly from JSTOR and it's given me the below:

Subject. (2021) Confounding Gender on JSTOR. Retrieved April 24, 2021, from https://www.jstor.org/stable/3175248?seq=1#metadata_info_tab_contents

The author's name isn't "Subject;" the article was published in 1997, not 2021; the title is "Confounding Gender," without "on JSTOR;" and the URL has tracking info. Also, although all this information is clearly listed in the open page, the citation skips over journal name, volume, number, and pages.

I understand it's difficult to program these things, but this extension just isn't ready.

Bug: Icon of "Cite This!" extension isn't displayed after installation (FF 66.0.3 with a few reasonable extensions installed).

BUT what is *really frustrating* is total lack of any (even very basic) information about usage. [Unfortunately, it is the typical fault of FF Add-ons developers :-( ]
1. No information that after installation there should be an icon (I've learned it from reviews), nor information what happens when you press the extension shortcut key (or - probably - click its icon).
2. No reference to information on formats of citations generated by the extension.
3. No usage examples (even screenshots).
4. Lack of information what is the result of extension action (less important, nevertheless, inconvenient; it could be added in the basic description perhaps in place of reference to the expected location of comments and feature requests...)