A few years ago, this add-on was reliably able to mark transphobes. These days, it's largely just spam, at least on the websites I use. On Wikipedia, it amounts to little more than a "No shit, Sherlock" (Wow, the Catholic Church is transphobic? I never woulda guessed). On tumblr, it has become a tool of the people who seek to divide the trans community. People who speak about issues faced by the intersex community, nonbinary community, or trans masculine community can get marked red despite saying nothing that is against trans people. This tool is now completely ineffective, and I cannot trust either the green or the red markings.

Edit: I dropped my review from 2 stars to 1 star. The reason is based on the comment the developer has been leaving on many complaints similar to mine. "Transmasculine, intersex and xenogender people are welcome. Just don't use "AFAB trans woman", as it forces trans women to use "AMAB" or "male", aligning your goal with that of TERFs." Transmasculine, intersex, and xenogender people are actively telling you that we are being made to feel UNWELCOME! All you're doing is saying "Well, you COULD come to this place where slurs against you are acceptable, where terms like 'theyfab' 'itfab' and 'afag' aren't enough to get you kicked out. You COULD come to this place where discussing your unique oppressions like your erasure from history and news reports and culture gets you marked as Bad. It's welcoming to you!"

It. Is. Not. Welcoming. We are not welcome to use this extension if we want to talk about our issues. If trans men just sit there and look pretty, then we're welcome. Wonder where we've heard that...