SwiftBites - Learn how to code in swift with interactive mini lessons
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.
udemy-dl - Download courses from Udemy for personal offline use
Magiclingua - Speak a new language with confidence
Amazon Kindle - Amazon Kindle software lets you read ebooks on your Kindle, iPhone, iPad, PC, Mac, BlackBerry, and...
Cambly - Private language tutors on demand.