The Observatory

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Every day a new word waits in the viewfinder. Learn what it means, how it's used and where it comes from, then master it with three quick challenges: Comprehension, Usage and Mastery. Each word becomes a star in your own galaxy, grouped into constellations by category. Review brings words back right before you'd forget them, and 3D companions react to every answer. Streaks, widgets and a weekly leaderboard with friends. The whole app works in English and Spanish. Free on iPhone and Android.

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