You’ve already seen this in numerous apps. Images that can be dragged by holding, enlarged, shrunken and rotated with the pinch gesture. All that being said, if you’re new to programming UIGestureRecognizers this can be a somewhat difficult task.
I’ve found a tutorial demonstrating how to easily include this functionality that is immensely useful for many different kinds of photo apps.
There is also an excellent sample project included.
The tutorial is from Roger Chapman and can be found here:
iOS Image Manipulation with UIGestureRecognizer: scale, move, rotate
Tremendously useful code if you are ever making any sort of photo manipulation app.
[via Alex Curylo]