App icon and launch screen in iOS Swift

Introduction

App icons and launch screens help users recognize your app and give a smooth start experience.

When you want your app to have a unique picture on the home screen.

When you want to show a simple image or logo while your app is loading.

When you want to make your app look professional and polished.

When you want to improve user experience by avoiding a blank screen at startup.

Syntax

iOS Swift

1. Add app icon images in Assets.xcassets > AppIcon.
2. Add launch screen storyboard file (LaunchScreen.storyboard).
3. Set launch screen in project settings under General > Launch Screen File.

App icons must be square images in multiple sizes for different devices.

Launch screens use storyboards or XIB files, not static images.

Examples

This is the main app icon used in the App Store.

iOS Swift

Add 1024x1024 PNG image named AppIcon in Assets.xcassets for App Store icon.

This storyboard shows your logo while the app loads.

iOS Swift

Create LaunchScreen.storyboard with an ImageView showing your logo centered.

This tells iOS to use your storyboard as the launch screen.

iOS Swift

In Xcode project settings, set 'Launch Screen File' to 'LaunchScreen'.

Sample App

This simple app shows a white screen after the launch screen. The launch screen and app icon are set in the project settings and assets.

iOS Swift

import UIKit

@main
class AppDelegate: UIResponder, UIApplicationDelegate {

  var window: UIWindow?

  func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
    window = UIWindow(frame: UIScreen.main.bounds)
    let viewController = UIViewController()
    viewController.view.backgroundColor = .white
    window?.rootViewController = viewController
    window?.makeKeyAndVisible()
    return true
  }
}

Important Notes

Tip: Use vector or high-resolution images for app icons to keep them sharp on all devices.

Remember: The launch screen should be simple and fast to load to avoid delays.

Accessibility: Ensure your launch screen has good contrast and no flashing content.

Summary

App icons are the images users see on their home screen and in the App Store.

Launch screens show a simple image or layout while your app is starting.

Set app icons in Assets.xcassets and launch screens with a storyboard file in project settings.

Practice

1. What is the main purpose of the app icon in an iOS app?

easy

A. To display the app's settings menu

B. To represent the app on the home screen and App Store

C. To show a loading animation when the app starts

D. To provide user notifications

Solution

1. Step 1: Understand what an app icon is

   The app icon is the image users see on their device's home screen and in the App Store.

2. Step 2: Identify the purpose of the app icon

   It visually represents the app so users can recognize and open it easily.

3. Final Answer:

   To represent the app on the home screen and App Store -> Option B

4. Quick Check:

   App icon = app representation [OK]

Hint: App icon shows your app's picture on the device [OK]

Common Mistakes:

• Confusing app icon with launch screen
• Thinking app icon controls notifications
• Believing app icon shows loading animations

2. Which file or folder is used to set the app icon images in an Xcode iOS project?

easy

A. Assets.xcassets/AppIcon.appiconset

B. Main.storyboard

C. Info.plist

D. LaunchScreen.storyboard

Solution

1. Step 1: Identify where app icons are stored

   App icons are placed inside the Assets.xcassets folder, specifically in the AppIcon.appiconset.

2. Step 2: Differentiate from other files

   LaunchScreen.storyboard is for launch screens, Info.plist holds app settings, and Main.storyboard is for UI layout.

3. Final Answer:

   Assets.xcassets/AppIcon.appiconset -> Option A

4. Quick Check:

   App icons = Assets.xcassets/AppIcon.appiconset [OK]

Hint: App icons live in Assets.xcassets, not storyboard files [OK]

Common Mistakes:

• Choosing storyboard files for app icons
• Confusing Info.plist with icon storage
• Not knowing Assets.xcassets purpose

3. Given the following code snippet in an iOS app project, what will the launch screen display when the app starts?

/* LaunchScreen.storyboard contains a centered image named 'LaunchImage' */
// No code changes to launch screen

medium

A. The image named 'LaunchImage' centered on the screen

B. A blank white screen

C. The app icon displayed full screen

D. An error because launch screen needs code

Solution

1. Step 1: Understand launch screen storyboard setup

   The LaunchScreen.storyboard has a centered image named 'LaunchImage'. This storyboard is shown while the app loads.

2. Step 2: Predict what appears on launch

   Since the storyboard shows the image centered, the launch screen will display that image centered on the screen.

3. Final Answer:

   The image named 'LaunchImage' centered on the screen -> Option A

4. Quick Check:

   Launch screen storyboard shows its content [OK]

Hint: Launch screen shows storyboard content, no code needed [OK]

Common Mistakes:

• Thinking launch screen shows app icon automatically
• Assuming launch screen is blank without code
• Believing launch screen requires Swift code

4. You set a launch screen storyboard but when running the app, the launch screen shows a black screen instead of your design. What is the most likely cause?

medium

A. The app's Info.plist is missing

B. The app icon images are missing

C. The storyboard file has syntax errors in Swift code

D. The launch screen storyboard is not assigned in the project settings

Solution

1. Step 1: Check launch screen assignment

   If the launch screen storyboard is not set in the project settings under 'Launch Screen File', the app shows a black screen on launch.

2. Step 2: Rule out other causes

   Missing app icons or Info.plist issues do not cause black launch screens. Storyboards do not contain Swift code, so no syntax errors apply.

3. Final Answer:

   The launch screen storyboard is not assigned in the project settings -> Option D

4. Quick Check:

   Launch screen file must be set in project [OK]

Hint: Always assign launch storyboard in project settings [OK]

Common Mistakes:

• Confusing app icon issues with launch screen problems
• Expecting Swift code in storyboard files
• Ignoring project settings for launch screen

5. You want your app to show a launch screen with a background color and a centered logo image. Which steps correctly set this up in Xcode?

hard

A. Write Swift code in AppDelegate to display the image and background color on launch

B. Add the logo image to Assets.xcassets and set it as the app icon; no storyboard needed

C. Create a LaunchScreen.storyboard with a view colored as background and an image view centered; assign this storyboard in project settings

D. Set the background color and image in Info.plist under launch screen keys

Solution

1. Step 1: Design launch screen in storyboard

   Create a LaunchScreen.storyboard file with a view that has the desired background color and add an image view centered with the logo image.

2. Step 2: Assign launch screen storyboard in project

   In Xcode project settings, set the 'Launch Screen File' to this storyboard so the system shows it on app launch.

3. Final Answer:

   Create a LaunchScreen.storyboard with a view colored as background and an image view centered; assign this storyboard in project settings -> Option C

4. Quick Check:

   Launch screen = storyboard design + project assignment [OK]

Hint: Use storyboard for launch screen design, assign in settings [OK]

Common Mistakes:

• Trying to set launch screen via Info.plist
• Confusing app icon with launch screen setup
• Attempting to use Swift code for launch screen UI