How to customize your app icon?

Overview

iOS 10.3 allows you to change your app icon programmatically. We can change our app icon programmatically.

Let’s get started.

Tool Used: Xcode 9.1, Swift 4+

Step 1: Setup Project

Create new Xcode project.

Write name of your project, we have use SwitchingAppIcon. (Make sure that you choose swift language) and Click on Next button.

Create two icons @2x and @3x for the iPhone, we named it as appicon_1@2x and appicon_1@3x. Add them in their appropriate places in the assets folder.

We can add alternative icons but not into the assets folder.

Step 2: Register Alternative icons

Register these alternative icons in our Info.plist. Add this to your Info.plist file.

For iPhone App

<key>CFBundleIcons</key>
    <dict>
        <key>CFBundleAlternateIcons</key>
        <dict>
            <key>appicon_2</key>
            <dict>
                <key>CFBundleIconFiles</key>
                <array>
                    <string>appicon_2</string>
                </array>
                <key>UIPrerenderedIcon</key>
                <false/>
            </dict>
            <key>appicon_3</key>
            <dict>
                <key>CFBundleIconFiles</key>
                <array>
                    <string>appicon_3</string>
                </array>
                <key>UIPrerenderedIcon</key>
                <false/>
            </dict>
        </dict>
        <key>CFBundlePrimaryIcon</key>
        <dict>
            <key>CFBundleIconFiles</key>
            <array>
                <string></string>
            </array>
            <key>UIPrerenderedIcon</key>
            <false/>
        </dict>
    </dict>

Make sure alternative icons are named without @2x and @3x prefix.

For iPad App

<key>CFBundleIcons~ipad</key>
    <dict>
        <key>CFBundleAlternateIcons</key>
        <dict>
            <key>appicon_2</key>
            <dict>
                <key>CFBundleIconFiles</key>
                <array>
                    <string>appicon_2</string>
                </array>
                <key>UIPrerenderedIcon</key>
                <false/>
            </dict>
            <key>appicon_3</key>
            <dict>
                <key>CFBundleIconFiles</key>
                <array>
                    <string>appicon_3</string>
                </array>
                <key>UIPrerenderedIcon</key>
                <false/>
            </dict>
        </dict>
        <key>CFBundlePrimaryIcon</key>
        <dict>
            <key>CFBundleIconFiles</key>
            <array>
                <string></string>
            </array>
            <key>UIPrerenderedIcon</key>
            <false/>
        </dict>
    </dict>

Step 3: Write some code

Create 3 buttons in our storyboard which will change between our icons.

Connect them in your ViewController and add this code to change app icons

// MARK:- Actions
extension ViewController{
    @IBAction func btnTapAction(_ sender: UIButton){
        // If false, alternate icons are not supported for the current process.
        if UIApplication.shared.supportsAlternateIcons {
            var alternateIconName: String? = nil
            switch sender.tag {
            case 2:
                // Change App icon 2
                alternateIconName = "appicon_2"
                break
            case 3:
                // Change App icon 3
                alternateIconName = "appicon_3"
                break
            default:
                break
            }

            // Pass `nil` to use the primary application icon. 
            UIApplication.shared.setAlternateIconName(alternateIconName)
        }
    }
}

Step 4: Test

Press on App icon 1 to set default App icon.

Press home button to see result.

Press on App icon 2 to set appicon_2 icon

Press home button to see result.

Press on App icon 3 to set appicon_2 icon

Press home button to see result.

Note:
Be careful to use a unique key name for each alternate icon

For more reference
– Apple Developer Documentation