Is anyone aware of a decent flashcard program that has a decent AI and learning system that is free? With my current Russian course, I have about 500+ words which I need to constantly review, but I am using a program called "MemoryLifter (v2.2)". It's decent, but the way they set it up is a little weird. It's either multiple choice or fill in the blank and you have to set it up yourself (which actually, I don't mind). The biggest problem for me is the words that I missed they don't weight so I focus more on them enough.
I'm curious what everyone else uses...