Http://nihongo-app.com/ the sentences are ordered in increasing difficulty too. Source: about 1 year ago

Http://nihongo-app.com I’m surprised no one ever mentions this app. I have both Pleco and this app I linked. I don’t think I would have consistently kept up with studying Japanese for the past 3 years without this app, tbh. Pleco is awesome, but I wish the flashcard system were better. They each have their pros and cons but the app I linked has what you want and more. Source: about 1 year ago

You should check out my other app, Nihongo (https://nihongo-app.com), it has functionality like this, and is one of the reasons I developed it in the first place. I take DRM free ebooks and copy them into the app one chapter at a time. It automatically creates flashcards for all the words that appeared that I don't already know, and I can filter down to only words that appear at least twice. - Source: Hacker News / over 1 year ago

You can check out my other app Nihongo for this too (https://nihongo-app.com). :). - Source: Hacker News / over 1 year ago

I'm also a fan of learning kanji only in the context of words, and not on their own in a vacuum. I made the kanji decks in my other app Nihongo (https://nihongo-app.com) based on this philosophy. Basically, they teach you (1) the kun-yomi word(s) for each character, (2) the 1-3 most common words for each on-yomi, and (3) to write the kanji. Don't try to learn the readings in isolation, learn them in the context of... - Source: Hacker News / over 1 year ago

Caption app (https://getcaption.co) can help you via Rosetta. Source: over 2 years ago