SkyView - SkyView is powerful, easy-to-use app that answers questions about stars, constellations, and more.
Stellarium - Stellarium is a free open source planetarium for your computer.
Solar System Scope - 3D model of the Solar System and night sky in real time
SkySafari - SkySafari is a powerful planetarium that fits in your pocket.
Celestia - Celestia - real-time 3D visualization of space.
Star Walk - Star Walk – Sky View: Explore the Stars.