Card2Memory is a flashcard tool that follows the Leitner system with 5 boxes and optimizes your learning process.
In the free version the number of files is limited to one.

A file with the basic knowledge of Analytical Geometry in German can be downloaded here free of charge.
You can use the card index by opening the loaded c2m file directly in Card2Memory or by sending the file to yourself as an e-mail attachment and then opening it with Card2Memory.