Please hold off updating to iOS8 until v3.5 of the app has been released, which may take a couple of more days.

If you however read this too late, make sure you enable “Location Services” for the app. Press Home, then
Settings->Privacy->Location Services(ON)->SkyChartsPro(Always)

If successful, when the app runs, you will have a little arrow in the upper right corner (next to the battery level).

More of the new iOS8 settings are explained here.

Since there are GUI problems in iOS8 (with v3.4), please refer to the help here for what the buttons are.

Hopefully v3.5 will be out on the 22nd.