App Icon size differs depending on where it is being used. As an App developer we need to prepare app icon of all the needed sizes or else our App will not ever be approved to the app store.
The best place to refer for a proper App Icon size is of course iOS Human Interface Guidelines page. But for myself I have created this little App Icon Reference table which is quicker for me to reference than to scroll a longer Apple’s guidelines page.
| Device | App Icon | App Store Icon | Spotlight Icon | Settings Icon |
| Phone 6 Plus | 180×180 px | 1024×1024 px | 120×120 px | 87×87 px |
| iPhone 6, 5, 5C, 5S, 4, 4S |
120×120 px | 1024×1024 px | 80×80 px | 58×58 px |
| Retina iPads Mini 2 & 3; Air 3 & 4 |
152×152 px | 1024×1024 px | 80×80 px | 58×58 px |
| Older iPads iPad 1, 2 & Mini 1 |
76×76 px | 1024×1024 px | 40×40 px | 29×29 px |
In this video below I am showing how to create a very simple App Icon and how to add App Icon to your app in Xcode. I know the example is very simple, so please do not be too critical :).
I hope this post was of some value to you.