BetterMemo

BetterMemo has a simple, yet powerful concept. It provides an algorithm, called spaced repetition learning. By studying this way, you remember more information, compared to when you hear the same information again and again. You will save your time reviewing the information less often, compared to a traditional learning. BetterMemo puts spaced repetition learning into action and helps to boost your ability to remember. The whole learning process includes three easy steps: enter the information you want to learn, review it when BetterMemo prompts you, and as a result - learn it better with each review.
Key features:

Organizing notes in folders;
Testing your retention;
Seeing your progress with various statistics.