I've been playing a bit more with trying to create an updated Spider Basic app icon. This time I used a proper SVG graphics program (Autodesk Graphic) on the Mac to achieve something a little more professional (I hope). For example, this version has a two-tone border and a drop shadow:
To be honest I am not sure what the formal requirements are for icns files. I just use a small app from the App Store called "Icon Tool for Developers" (free) that resizes a source image into all the required sizes and bundles them up.
I don't have access to any retina Macs so I'm afraid that I cannot test to see whether the icons look OK on those - maybe somebody else on the forums with a retina Mac could take a look for us?
Note: if you are not using asset's catalogs when you added to the app you just need to double check the naming conventions, like e.g. icon_32x32.png and icon_16x16@2x.png are having the same physical size but the first is not for retina screen but the second one is, so the naming convention helps the system to identify which icon should appear in a certain situation.
I think that is probably correct though: as the image was created on a non-retina Mac, it probably uses the 32x32 for a retina 16x16 to keep the detail? Sound about right?
