This extension does exactly what you need it to do, so why the 1* review? AI and data mining, that's why.

I installed this because Firefox's own spell checker kept failing. Upon installation it requires you to accept their "very broad" scope for monitoring (ie: data mining) as in it monitors every single page you visit (irrespective of whether the extension is used on that page), meanwhile it offers up AI solutions to every situation.

All round an average product totally hampered by extremely poor data mining and AI support. Absolutely no trust should be extended to this extension or the company responsible.

Nothing here is "illegal" but it is "dodgy". Install at your own risk.