Japanese Vocabulary is, not surprisingly, an application for studying Japanese vocabulary. It consists of a set of cards, each with 3 pieces of information on them. The 3 pieces of information are the kanji spelling, kana reading, and English (or other languages) meaning. It uses the Leitner system for managing the cards, which means that you see the cards you know well less often than you see the ones that you don't know very well.
One World Dictionary by Ascendo is a leading multilingual reference tool for Apple desktops.
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