On iOS, you can change the 1SE app icon. Go to the Profile tab, scroll down, and tap Your Perks - Unlock Custom App Icons!
Scroll down to see the custom app icons and select any available icon. The more snippets you add, the more icons you'll unlock.
We use the total sum of snippets you have added across all your Journal projects to unlock the icons. We don't count snippets in Freestyle or Freestyle Collab projects in this total.
To reset the app icon to the original, open the icons section and select the Default icon.
You might have to restart your phone to see the icon change on your home screen.