Quizzes: you can create quizzes and take quizzes. You can take your
own quizzes or any quiz that has been made public by the author.
Flash Cards: you can create flash card decks and "play" the flash
cards. You can self-report on which ones you answered correctly
and which ones you missed, and the application provides you with
the option to use that data to customize your future study sessions
with that deck.
Cheatsheets: these are notes, long or short, that you can tag with
keywords to help you find them later on. The search capability
allows you to search via tag name or words in the title or content
of the cheatsheet.
What Does It Use?
Ruby version: 2.1.1
Rails version: 4.1.1
jQuery (heavy use of it for playing a flash card deck, light use elsewhere)
Ajax (but only for the CRUD operations of flash cards [not the deck, just the cards])