Moving and zooming in Galaxy View is slow and jerky in SkySafari 6 Pro on my iPad Air 2. I only noticed this since upgrading to iOS 12 and don't remember it being like this on iOS 11.
Here is a screen recording showing zooming. I tapped Auto zoom with the view already centred on the sun. https://www.youtube.com/watch?v=SzwAlsh3m_I
Restarting the iPad and reinstalling SkySafari didn't make any difference.