Once I got the icon approved for the Mac App Store, I switched to using the same icon in the iOS version (now in beta). But the icon that worked on the desktop didn’t look good on the iOS devices. The image part of the icon wasn’t square and after the iOS rounding and shading had been applied, it looked a bit weird.
So I went back to the original image, removed the white space around the edges and squared it up. It needs a bit of tweaking still, but here is a shot of it on my iPad screen.