Harken - Flashcard app using smart repetition to improve your memory
Pocket - When you find something you want to view later, put it in Pocket.
Taggy - App for fast saving anything without losing focus
Keep Everything - Light & Fast Web Archiver for iOS, OS X.
WebSatchel - Copy and save web pages to your own personal archive
Instapaper - Instapaper is a simple tool to save web pages for reading later.