I have not seen anybody mention the app “kakugo” [https://play.google.com/store/apps/details?id=org.kaqui&gl=US](https://play.google.com/store/apps/details?id=org.kaqui&gl=US)
its a free open source kanji, vocab, kana app. it uses spaced repetition
it free and open source available on play store and fdroid
not sure about ios stuff as thats not my thing
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Been using it alongside anki and can say my reading and recognition of kanji is getting much better rapidly
it uses a newer srs algo that means you can pick up if you fancy it or ignore so no extra pressure as anki is enough i find
but on those days where you fancy extra exposure you can blast out 1-200 reps pretty quick