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Comprehensive reference tool with games and customization.
Devices: iPhone, iPod Touch, iPad, Android, Chromebook, Kindle Fire
Excellent tool encourages appreciation of the universe.
Devices: Android, Apps for Windows
Comprehensive tool with voice search, fun daily features.
Devices: Android, Apps for Windows, Windows Phone
Delightful way to learn about animals, people, and more.
Devices: iPhone, iPod Touch, iPad