Chat-Specific Wallpapers. Your favorite photos and color combinations can become unique backgrounds in any 1-on-1 chat. After setting a wallpaper, a special message is sent that allows your chat partner to add the same wallpaper on their side. To set a custom wallpaper, tap ➕> ‘Set Wallpaper’ on Android, or open a profile and tap ➕ > ‘Change Wallpaper’ on iOS.