This post comes at a perfect time because I am working on an app that utilizes spaced repitition and flash cards and happen to be tweaking the spaced repition algorithm today. I've used Anki a quite a bit, and it mostly works but there are limitiations and things that don't work well. The post does a good job at highlighting some of the underlying issues.

The app I am working on is focused on language study. A big drawback of Anki when it comes to language study is that the card is tightly coupled to the content it's trying to teach you.

In our implemntation, we decided to decouple the presentation of what you're studying and how you're studying. We have the concept of a term which can be a word, definition, sentence or character. We store the progress information along with term. The term can then be studied with any of the available study methods. This gives quite a bit of flexibility in how the information is studied and reviewed and goes a lot further than just flash cards and multiple choice questions.

Another benefit is that this progress information can then be used to make recommendations to the user on what to study next.