The ability to modify iPhone’s hardware buttons is the very first thing the developer, Yu Jin, advertises in his app’s description, saying, “Turn iPhone Volume Button into a Shutter Button? ‘Quick Snap’ is the app for THAT!”
He adds, “Why choose the soft or full screen shutter when you can use VOLUME BUTTON as the hard shutter button on your iPhone? You are now one step close to the real digital camera experience! Isn’t that awesome?”
Two screenshots for the app on the App Store
This is the kind of feature that many iPhone photographers want, as touching the screen can sometimes jiggle the camera. The problem, however, is that Apple’s developer rules specifically forbid ever using the hardware controls in “non-standard” ways. This is part of Apple’s legendary control over its devices, as it seeks a uniform experience for users (for better or worse).
Wired magazine pointed out that this was referenced in the rejection letter Apple sent to Tap Tap Tap when the company included the same feature in its app, Camera+.
“Your application cannot be added to the App Store because it uses iPhone volume buttons in a non-standard way, potentially resulting in user confusion,” Apple said in its August rejection letter. “Changing the behavior of iPhone external hardware buttons is a violation of the iPhone Developer Program License Agreement.”
Camera+ was eventually allowed back into the App Store without that feature.
It’s unclear if this marks a change in Apple’s policies, or if Quick Snap merely slipped through the approval process. As it is, the app is still available as of this writing for US$1.99. If you want it, you might want to consider getting it sooner, rather than later.