iOS 17 Contact Posters is a default handler for phone in ios 17 style Making your contacts dial pad call interface and incoming call interface to have the newest style of ios 17.
First of all you need to set the app as the default handler for phone in order to have operating authority.
Among the new features: The contact posters can set up an exclusive full-screen background call show for different contacts which is very visually impactful and makes the incoming call feel completely new.

Poster setting steps: Contacts - Select Contact - Contact posters - Change Poster