Grammarian PRO3 - Grammarian PRO3 is a feature-rich grammar checker that enables you to write better content without taking assistance from the English teacher.
Lexi - Speak to Alexa through your iPhone
Gramlee.com - Online grammar check, proofreading and copy editing services.
Astra by Cesbo - Talk to Alexa anywhere, from your iPhone
LanguageTool - Free proofreading tool for OpenOffice, LibreOffice, Firefox, and Chrome.
Ava - Making conversations accessible for the deaf