Hit the three dots and select Add to Home Screen.
Select the Choose Photo option to open up your Camera Roll and select that icon you chose for this particular app in step one.
To get rid of the old app icons, long-press your home screen to send them to the App Library.
But if you want your iPhone to reflect your true spirit, it might be worth the hours it takes to fully trick out your home screen.
Save the icons to your camera roll.
Hit the three dots and select Add to Home Screen.
Select the Choose Photo option to open up your Camera Roll and select that icon you chose for this particular app in step one.
To get rid of the old app icons, long-press your home screen to send them to the App Library.