One of the troubles to develop iOS app is to prepare different sizes of app icon images. iOS allows user to see your app icons in different places.
- Home Screen
- App Store
- Spotlight
- Setting
- Notification
Depending on what iDevices (iPhone or iPad) your app support, you are required to provide different size of image.
Checklist
There are 9 images for iPhone, 9 images for iPad, 14 images for iPhone & iPad. A suggested naming of the icon image is AppIcon60x60.png Applcon60x60@2x.png AppIcon60x60@3x.png
The below image is another checklist of app image.
Reference: https://developer.apple.com/ios/human-interface-guidelines/icons-and-images/app-icon/