Cloud to butt, xkcd word substitutions
What it does
We made a list of common grammatical errors (and other annoying things), and each time the extension sees one of these it swaps it to the other one (with about a 30% chance, so as to keep some subtlety).
How we built it
Forked cloud to butt plus, implemented a bunch of substitutions
Accomplishments that we're proud of
Making the world a worse place.
What we learned
Always remember to double escape if you're using new RegExp
Some extensions don't work because they haven't been touched in years and shouldn't be forked.
What's next for Grammer Ungooder