Anki user here, for about 5 years now studying Korean and to a lesser extent Japanese and miscellaneous topics.<p>This is cool, but I will never base my learning on a closed-source product. I simply don't trust anyone with data / workflows this important to me.<p>Anki doesn't have great UX, but it is -dependable-. It works, day in, day out, and I've had zero issues with it. I trust that in 5-10 years, my anki decks will be there and work exactly the same.<p>edit: I'm not trying to be negative. I think there is a lack of spaced repetition-based flashcard apps with great UX. However I personally value stability and guarantee of longevity over nice UX. If the developer of Anki quits tomorrow, it being open source ensures that it'll live on with new maintainers (even if that's just me).