google.com/store/apps/details?hl=en&id=jp.jfkc.KatakanaMemoryHintApp.En
App teaching katakana through mnemonic pictures, animations and sound, with quizzes and a reference chart. Designed for complete beginners and those learning Japanese characters.
Kanji and kanaEducational gamesApps and toolsKatakanaKanji mnemonicsQuizzesAppsPronunciationHiraganaCalligraphyBeginnerListening practice