TokeiTango is a flashcard app designed for the Apple Watch, focusing on teaching over 9,000 common Japanese words. The app's name originates from the Japanese words for "watch/clock" and "word," symbolizing its educational purpose. The compact nature of the Apple Watch is utilized to provide short study sessions, ideal for quick learning moments during daily activities.

Key features of TokeiTango include a spaced-repetition algorithm for effective learning, word bookmarking for later reference, customizable word learning order, card color theme options, detailed statistics tracking progress, audio output for pronunciation practice, example sentences for context, watch face complications for continuous learning, and daily study notifications.