> This extension will check your text by sending it to https://languagetool.org over an encrypted connection. Your text will not be stored.

Gives me a "privacy policy", "continue and don't ask again" or "cancel" hyperlink, nothing else. If I want to use it the first time.

But if you open the extension options under the "more tools" > extensions tab you can set the LanguageTool API server URL[0].

Going to try to setup a server over the weekend, thanks.

[0]: http://wiki.languagetool.org/http-server