Much more through and intuitive than any other grammar and spell checker I have used.

I like that it still allows custom sources.

Really nice, and for me at least, it even seems to be free!

This is a very useful add-on to Firefox. It's much more than a spelling checker, having a very good grasp of grammar and a reasonable ability to determine which word you meant to type. It's not perfect, but it's an excellent tool, as long as you don't follow it blindly.

El millor corrector de català del món.

Seems to do its job and stay out of the way... key for any grammar and spelling checker. Funnily enough it doesn't work in this box 🤣