Although dated, you may want to check out FSI (Foreign Service Institute) at
http://fsi-language-courses.org/Content.php.
Open Culture has a collection of resources for various languages (
http://www.openculture.com/freelanguagelessons) that might get you going in the right direction.
I keep requesting access to the Kindle Developer API, so that I can write myself a flashcard app (I'm a programmer by trade), but they keep ignoring me.
