SmartCards+ - Spaced Repetition Software for iOS. Modern, powerful and easy to use.
Pocket - When you find something you want to view later, put it in Pocket.
FlipToMind - Space repetition app to help you remember everything
Keep Everything - Light & Fast Web Archiver for iOS, OS X.
Zorbi - Spaced-Repetition Flashcards - Other tools are built by boomers, Zorbi is built by students.
Taggy - App for fast saving anything without losing focus