Firefox will not use it and states only US pack available for my locale. So uses US spellings. I want to use British English!

ca ne marche pas

Says it's installed but it simply doesn't work. Spell check still marks UK spellings as wrong.

no matter WHAT i do, firefox ALWAYS resorts to USA spelling.

Quite incomplete but better than anything else free out there & I appreciate this author's maintenance over the years.

Doesn't work. I can write any spelling at all on Twitter and it does nothing.

It do nothing. I have installed the English pack and I still only have the Swedish dictionary.

There have been a few instances where certain forms of a word are detected as false positives, but those are low enough to not be inconvenient. (I have only experienced the dictionary part of it - in case there is more to it)