Pocket - When you find something you want to view later, put it in Pocket.

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.

Keep Everything - Light & Fast Web Archiver for iOS, OS X.

SmartCards+ - Spaced Repetition Software for iOS. Modern, powerful and easy to use.

WebSatchel - Copy and save web pages to your own personal archive

Zorbi - Spaced-Repetition Flashcards - Other tools are built by boomers, Zorbi is built by students.