This add-on seems to be overwritten by the English (US) language - very frustrating when the spelling check underlines the correct spelling for English (UK) words in favour of English (US) - exactly like it's done here for 'favour'!

Constantly reverts to US English. This is so annoying that I may well have to ditch Firefox altogether. PLEASE rectify!

It helps me see my typos and to spell better.

It doesn't work...

Finally Firefox in English. It's getting more of a pain to wrestle it out of American.. It just shouldn't need this though. V18 improves getting this horrible browser (it was great once) and LibreOffice installing in British immediately.

er, it doesn't seem to want to install on firefox quantum 63.0