Yokatta© is an open-source flashcards based language learning app using spaced repetition. The algorithm is heavily influenced by SuperMemo's SM-2 and follows best practices using Android Architecture Components provided by Google. App features: * selectable themes * randomize order of flashcard during review * review animation for visual feedback * "sligtly-off" toast when answer submitted is not quiet correct * haptic feedback when submitting an empty answer * recording pronunciation * double press "back-button" to exit review * auto focus input field * display diagrams to show how many review items have been taken * swipe gesture to delete/modify existing flashcards * swipe gestures to easily delete/modify existing flashcards * search a specific flashcard * export flashcards to JSON Open source repository: https://github.com/uestueab/app-thesis