Smartr Lite is the free version of Smartr, a learning tool and study aid that allows you to create stacks of cards with information that you want to learn, and then study them like flashcards. Only these flashcards are smartr:  In your study sessions Smartr quizzes you on cards that are carefully selected for you based on your past performance, what you need to study, and when. 
When creating a new stack of cards, you can choose to have one stack per subject, class, book, or chapter of whatever it is you are studying. You can also choose each card type within the stack. Some example card types include “Question and Answer”, “Definition”, “Picture Identification”, “Japanese Kanji Vocabulary."
Smartr Lite is free and has a limit of 100 cards. If you like it, check out the full version of Smartr and create as many stacks with as many cards as you like.