I like the extention, tough there is one flaw I've noticed when Using it with Firefox...
If I rightclick on a word that Grammarly selects to "correct" it there is a 70% chance that the word isn't changed but gramerly pastes the correct spelling at the location where my cursor is... this isn't usefull at all (example, I write "hello, how is you day going" and it should correct you to your, if I would correct that after typing going grammerly would change it to "hello, how is you day goingyour" :/)
Please fix this bug as it makes the application almost unusable and more of a nuisance than anyting else