einstein

Einstein is a software designed for Mac OS X only which allows you to store lots of questions (and eventually answers), then make up a quiz (random or not) and test you.
For instance, a student can type the main part of his lessons and evaluate his knowledge by himself.
With Einstein, you can also import and export sheets.

That's to say, a teacher could use it to make tests with answer keys at the same time, export a study sheet so that the student just have to put it into his Einstein program then test himself.