Análises para Corretor Gramatical e Ortográfico - LanguageTool
Corretor Gramatical e Ortográfico - LanguageTool por LanguageTooler GmbH
Análise por Pepper
I downloaded it because it advertised itself as working for multiple languages. While it did appear to work fine for English and French, it unfortunately failed to catch basic Japanese grammar mistakes such as missing particles and misspelled words. Given that I need this most for Japanese (as that is my weakest language at the moment), I have decided to remove it from my browser.