very good

The tool works perfectly. It was so convincing that I took the premium version. The only real trouble I have with the tool is, when I write text in a language that it does not correct or when I write multi-language texts.

Este es un muy buen corrector ahora escribo sin ningún error, si pudiera darle 100 estrellas se las daría.

cool

Отличное дополнение. рекомендую=-)

Great addition to a fabulous browser.

Supremely cool. I've been using languagetool for more than a year, and it slaps! Easy 5 stars.

Incrível, um amigo me recomendou a extensão e com menos de uma semana já adorei :)

Denke dass die guten Bewertungen allgemein zutreffen, ich habe ihn erst heute eingesetzt.

Installed b/c my spellcheck stopped working in Facebook posts.
Almost perfect- Excellent for grammar & spelling.
Even corrects my most repeated error (typing form when I want from, which other spellchecks ignore b/c they are both correct spelling).
However, the way it works by opening a new tab & having to return to comment and then copy/paste, instead of making corrections inside the comment is not ideal.
A pop-up window would be preferable if in comment corrections cannot be done.

I see your response but see no way to reply.
I was trying to use LT in FACEBOOK comments. I did not try it in Twitter yet.. UPDATE: works perfectly after re-install on FB & Twitter-
added a star..