Pretty good, misdirected a little Rated 4 out of 5 stars

But I think multiple dictionary support would be good, youtube comments are sometimes in British english and American english, whitelisting of words, for people who don't really mind stuff like im instead of I'm.

And I'm not sure if it knows the difference between a spelling mistake and a word it doesn't know. Maybe checking the comment against a bad list would work better than checking it against a dictionary.

This review is for a previous version of the add-on (1.3).