In the interim, literally dozens of other app developers created photo-related apps--exposure adjustment and cropping here, special effects and filters there. Now, Apple has built and polished its own interpretation of the ultimate photo app for its iOS devices.

The result is iPhoto for iOS, and it is worth the wait. The beauty of iPhoto for iOS is that, at its core, it's iPhoto by different means--very easy to learn and use, while retaining and simplifying the best attributes. It does not match the Mac program feature-for-feature, but its overall functionality is so similar, that users of the desktop version will instantly recognize the app's conventions and parameters and what it can accomplish.

The program works on the iPad 2 or later and the iPhone 4 or later, but disappointingly, not on the iPod touch--not even one with a built-in camera. Each mobile version feature is distinctly tailored for the device you're using. The iPad and iPhone interfaces are similar but not identical, and the subtle variations between the two versions work in the user's favor.

That's because the differences between the phone and the tablet programs relate exclusively to screen size. Almost every function available on the iPad version is present on the phone--except two: The magnifying Loupe and the Coaching Tips. The Loupe tool, called on to enlarge discrete parts of an image on the iPad, is not present on the iPhone. Coaching Tips--labels that identify each of the tools and functions--work well on the tablet, but like the Loupe, would overwhelm the small phone screen.