Features: - 123 levels teach, train and test your knowledge of all 88 constellations defined by the International Astronomical Union. - 180 levels teach, train and test your knowledge of 150+ brightest stars of the sky. - NEW! 153 levels teach, train and test your knowledge of 110 Deep Sky Objects (Messier Objects). - Create your own list of constellations, stars and DSOs for learning and practice. - Save and load your personal presets. - 7 default presets (e.g. zodiac constellations & navigatio