Grammarly - Clear, effective, mistake-free writing everywhere you type.
Forvo - Forvo: the largest word pronunciation dictionary in the world, now with translations.
LanguageTool - Free proofreading tool for OpenOffice, LibreOffice, Firefox, and Chrome.
PronounceItRight - PronounceItRight, establishes order in the huge phonetic mess of global communications.
Editsaurus - Highlights potential pitfalls in your writing to encourage good habits.
Howjsay - Pronounce words correctly with the world’s largest English pronouncing dictionary.