I'm developing an app around spaced repetition as well, for couples to learn each other's languages. I made the spaced repetition "multiplayer", so the native s

I'm developing an app around spaced repetition as well, for couples to learn each other's languages. I made the spaced repetition "multiplayer", so the native speaking partner can create appropriate flashcards or check in on the learner, or the learner can ask help from the partner. As some have mentioned, and what I went through, is spaced repetition is as good as the content, and often I made cards for learning Chinese that were like...ancient-style speaking Chinese. And then for things like languages, spaced repetition can only be a foundation, but needs to be augmented by real world practice. https://learncoupling.com https://learncoupling.com