Stellarium - www.stellarium.org/
Stellarium is a free open source planetarium for your computer. It shows a realistic sky in 3D, just like what you see with the naked eye, binoculars or a telescope.
It is being used in planetarium projectors. Just set your coordinates and go.
Heavens Above – Android App
This application reveals all iridium flares and satelittes (including international space station and amateur radio satellites) passing by at your location.
An auto-adjusting compass pointing in the direction of the satellite or flare helps you tracing the object.
Notifications can be enabled to warn you whenever a satellite of interest passes by.
Google Skymap – Android App
Point your phone at the sky, and Google Sky Map will show the stars, planets, constellations, and more to help you identify the celestial objects in view. You can also browse the skies in manual mode.
*NEW* Satellite AR – Android App
Point your phone at the sky and find actual satellites flying overhead. Ever wondered what satellites are flying above your head when you look up? This app will show them to you using augmented reality. Point your phone’s camera to the sky, and small icons track the locations of various satellites. Those in sunlight are colored yellow to help you look for them on a clear night.