Writing for Macworld, Marco Tabini explains how the parallax effect in iOS 7 works. I find animated backgrounds needlessly distracting (including those on iOS 7) but parallax really seems to add something to the experience of using the phone, even if it’s more of a feeling than functionality.

Although the exact details of iOS 7 are still under wraps, it’s clear that Apple intends for parallax display to become pervasive throughout its operating system (which may explain why the iPhone 3GS and first-generation iPad, neither of which has built-in gyroscopes, didn’t make the OS’s compatibility list).

At least in the current beta, parallax also doesn’t work on the iPhone 4, which had been my test device until I started using it on a 4S today. That may change before the final release. Apple lists which features will be available on which devices at the bottom of this page, but parallax isn’t one of the features detailed.