The iPhone Ultra will be unveiled at the September 9 event, debuting seven years after Samsung's first foldable. Three key features should make the wait worth it.

First, Apple aims for a virtually crease-free display. While a faint crease might be visible at certain angles, the inner display should largely look entirely crease-free when unfolded.

Second, the iPhone Ultra will be ultra-thin without compromising battery life or performance. The iPhone Air was a stepping stone, and the A20 Pro and C2 chips, plus a vapor chamber, will deliver solid battery and impressive performance.

Third, the hinge will use liquid metal, a technology licensed by Apple over 15 years ago. This should create a durable and smooth hinge that stands the test of time and heavy use.