This hides annotations by default as it claims, but it also slows down the browser majorly. When I restart Firefox and restore tabs from my previous session, this extension processes every tab one by one, and it hangs the rest of the browser until it has finished. With my hundreds of tabs, this prevents Firefox from loading any page for two minutes. Thus, it’s not worth using unless you configured Firefox to forget all tabs when you close it.

Also, the code of this extension is poorly organized to the point of being obfuscated. It is hard to check by reading its code whether this extension is doing anything nefarious with the permissions it has. I am worried that ‘background.js’ in this extension might be logging the URLs of all my open tabs and sending it somewhere, especially since the code isn’t open source and the author has no public presence. It’s more likely that the author is just a beginner coder though.