Function to dinamically change app's icon on iOS and iPadOS devices that support alternate icons.

ChangeAppIcon.swift

import UIKit

/// Changes the app's alternate icon.
/// - Parameter iconName: The name of the alternate icon. Pass `nil` to reset to the default icon.
func setAlternateIcon(_ iconName: String?) {
    guard UIApplication.shared.supportsAlternateIcons else {
        print("Alternate app icons are not supported on this device.")
        return
    }

    let iconToSet = (iconName == "Mac") ? nil : iconName

    UIApplication.shared.setAlternateIconName(iconToSet) { error in
        if let error = error {
            print("Failed to set icon: \(error.localizedDescription)")
        } else {
            print("App icon changed successfully to: \(iconToSet ?? "Default")")
        }
    }
}