One very obvious use of the button is to connect it to the iPhone's camera app, letting you press and hold to open the app, then press once more to take a picture. But does that mean the Camera Control button has made it obsolete? I don't think so.
To begin with, you can set it to do simple things (by using Settings > Action Button), like flick on the flashlight, set a Focus Mode, or open Apple's Translate app. With iOS 18, Apple added the ability to map it to a Control Center action or recognize a song with Shazam.
But you can go way beyond simple. For me, it's a way to help me use my phone less. It's something I'd been trying to figure out through other means, like adding Shortcuts to my homescreen, but the Action Button has been the missing part of a puzzle I'd been piecing together for years.
Now I use the button several times a day: long-pressing it to get to an option that turns all the lights off before I go to bed; selecting multiple AirPlay speakers at once in an easy-to-use menu format that waits for me.
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