1. Open the Shortcuts app.

2. Add a new shortcut.

3. Click the "Add Action" button.

4. Click on the "Scripting" option.

5. Click the "Open App" button.

6. Choose the app you want customized.

7. Click the "..." icon.

8. Click the Add to Home Screen button.

9. Choose a name, then tap the icon.

10. Click the Choose Photo button.

11. Choose your icon, then hit Add.

12. The icon is added to your home screen, Done.