Grammarly - Clear, effective, mistake-free writing everywhere you type.
Writing Prompts - Never run out of writing ideas again
LanguageTool - Free proofreading tool for OpenOffice, LibreOffice, Firefox, and Chrome.
Prompts - Build a better writing habit
Editsaurus - Highlights potential pitfalls in your writing to encourage good habits.
Riku.AI - Riku offers you a single playground to use multiple AI providers.