You're welcome! :) In building this app, we didn't survey the research addressing that question specifically (though googling "L1 vs L2 flashcards" pulls up so

You're welcome! :) In building this app, we didn't survey the research addressing that question specifically (though googling "L1 vs L2 flashcards" pulls up some interesting sites). For me personally, speaking from 15+ years learning French, Chinese, and Turkish, it's native --> target. Learning that way helps me recall faster when I need to construct my own sentences. If you're looking just to learn to read, I think target --> native is easier and might be a better approach. I've also had success starting with native --> target to familiarize myself with the word, then quickly switching to target --> native to solidify my ability to produce it on my own.