Sky Map

Hold Sky Map up towards the night sky and it shows you what you are looking at: stars, planets, constellations and the lines drawn between them. Move the phone around and the map moves with you, so finding Orion or working out which bright dot is Jupiter takes seconds.

This is the app that launched as Google Sky Map on the very first Android phone. Google stopped working on it in 2011 and let the original developers open source it, and the same people still look after it today.

It shows its age in places, and the developers are working on a refresh. How well it lines up depends on your phone's compass, which can drift; if the sky looks rotated, that is usually why.