If you need to find Sun position at a specific date or time, you can do it using only an Android device. There are many apps that can show you the position of the Sun from your location or from any other location using phone gyroscope sensor and GPS.

From simple tasks, like positioning your umbrella on the beach, to complex stuff regarding building decision, or just for fun, getting the sun position is, in my opinion, on of the greatest things that you can do with your Android phone.

You can view the sun position on the map, or you can view it on the camera while you point your phone in any direction you want.

A great app to do that is Sun Locator Lite.