Grammarly - Clear, effective, mistake-free writing everywhere you type.
ProWritingAid - For the smarter writer. A grammar checker, style editor, and writing mentor in one package.
Gramara - AI grammar correction with transformers
Andy Chatbot - Learn and practice English with exercises, grammar and games
LanguageTool - Free proofreading tool for OpenOffice, LibreOffice, Firefox, and Chrome.
Linguix - AI-enabled writing tool for writers, editors, and businesses