Granted this add-on has bugs, it's still extremely useful for me since I have a nasty habit of pressing send before realizing I mistyped one word in the whole paragraph.

The added benefit of being able to go to the website via the extension is a nice short cut. The website has a few more features that comes in handy, but the add on alone has:

spell check/correct
mood/tone
grammar check
btw, I'm using the free version.

As for the bugs. Sometimes the words don't auto correct, but add the correct writing at the end of the misspelled word. The add-on doesn't work on all websites or documents. The logo for the add-on appears in the bottom right of all applicable word boxes, which can also be where an important button may be (like the send or emoji button.)

Not working at all in Google Docs. I configured all the settings and did all the personalizations as well, and it is still not working in Google Docs. Though it is working on other online text editors. But my primary usecase was for writing emails and making scientific papers on Google Docs, where this extension failed critically.

very much not working for me pls check

Good

It had a lot of bugs and instead of replacing a word, it would put the word at the end of the sentence making it annoying to have to correct it's mistakes.

This undead add-on intrudes on _every_ text box, yet FF states that it's not installed. Am I cursed for eschewing the upper case? If I ever added it, I've since removed it. Its omnipresence taunts me.

When using with Google Docs, the highlight in the text field shows less than half the times it's supposed to, while in Edit mode. When using the side bar to select corrections, if they are not highlighted the document scrolls down to random pages some times. And sometimes when going back to the document from the side bar, it had a yo-yo effect when trying to scroll at first.