Alexa Skill Kit - Effortless Alexa Skill development with AWS Lambda
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.
BotTalk - Create Alexa skills and Google Assistant actions with Markup
BoldVoice - Accent coaching app for non-native English speakers
OK Google - Explore over 150 Google Now voice commands in one place
Andy Chatbot - Learn and practice English with exercises, grammar and games