Duolingo - Duolingo is a free language learning app for iOS, Windows and Android devices. The app makes learning a new language fun by breaking learning into small lessons where you can earn points and move up through the levels. Read more about Duolingo.
Grammarly - Clear, effective, mistake-free writing everywhere you type.
BoldVoice - Accent coaching app for non-native English speakers
Grammarian PRO3 - Grammarian PRO3 is a feature-rich grammar checker that enables you to write better content without taking assistance from the English teacher.
Andy Chatbot - Learn and practice English with exercises, grammar and games
GrammarChecker.net - Grammar Checker is an online spell check tool. It effectively works on English sentence correction, Punctuation mistakes of 28 other different languages.