1. Open your app store, such as Apple Store or Google Play Store.
2. Type "Whale Boy Animated Wallpaper" in the search bar.
3. Select a suitable app to download.
4. After installing the app, open it and select your favorite Whale Boy Animated Wallpaper.
5. Click the "Download" button and wait for the wallpaper to finish downloading.
6. After the download is complete, you can set the wallpaper as your phone's desktop.
Please note that different app stores and apps may vary, so you will need to do this according to your specific situation. Also, you need to make sure your phone system supports the dynamic wallpaper function.