[wingerlang]

Learning language is much more than drilling vocabulary. And I say this as someone who has built at least 3 different flashcard apps for myself over the years. It is very low down on the list, especially if it is words only.

And no, it doesn't seem like iOS gives us access to its dictionary as developer, unfortunately.

[Forricide]

That's unfortunate. I'm lucky enough to have studied my target language on & off for over a decade and one of my main issues at this point is vocabulary. But you're not wrong - it's not useful for everyone.