Honestly, this is a pretty good extension for it being free. Some people complain that it can't detect it being in a sentence or apart but actually I have a fix for that, just add a space before the word and a space before the replacer word and put a space bar in front of the word and the replacer word and voila it's fixed. I also have a bug to report, when you add a space to specified words before and/or after it makes removing the correction impossible, so if you accidentally misspell the replacer word you won't be able to remove it. this review is already getting long enough so I'd rate it 5 stars for utility and price, 4 stars for convenience.

I think the average rating for this extension should be higher.

As a result of trying several similar extensions, at the moment,
With the Firefox add-on,

"You" extensions and
Developer "Marc" extension
"Only" works correctly.

For non-English speaking people, simple and intuitive add-ons are more convenient.

It would be perfect if could re-edit the word already specified.

Thank you.