All iPhones incorporate a magnifier interface that can enlarge things for the hard at seeing. It tends to be useful for getting a closer look at fine text on a sheet of paper such as a book or shopping receipt.
In iOS 14 and earlier, the Magnifier interface can be summoned via accessibility using Control Center or a manually planted Home Screen icon. However starting with iOS 15, the Magnifier interface debuts as a standalone app on the Home Screen right out of the box.