Image resolution is optimized for the iPhone or iPad, which automatically reduces the resolution of photos synced via iTunes from most DSLRs. So what might have originally been a 12-megapixel image shot with your camera will arrive on your device as a 3-megapixel image in iPhoto for iOS. That's acceptable for some people, especially for online viewing. But, if you want the program to edit your images at full resolution, you must import them directly from your camera card via Apple's . Like iPhoto for the Mac, iPhoto for iOS accommodates images of up to 19 megapixels. It does not edit Raw photos, however.

The iPhoto for iOS interface is intuitive, with all actions accomplished on the tablet or phone via Apple's multi-touch gestures. If you're familiar with onscreen iOS conventions, the on-screen tap, pinch, and swipe actions will come as second nature. It took me less than 15 minutes to access each of the app's many features and controls and figure out how they worked--without a glance at the written documentation.

The app is driven by unlabeled icons at the top and bottom of the screen with a large Viewer in the middle. This might look intimidating at first. However one of those icons, a circle with a question mark inside it, serves up a screen full of contextual coaching tips that explain the operation of each control. In default mode, you see general tips. In Edit mode, you see tips that relate to editing controls. If you're in one of the editing controls--say, Exposure--you'll see only tips related to Exposure.

As you tap on each of the individual controls--Crop & Straighten, Exposure, Color, Brushes, and Effects--additional animations give visual clues as to how to proceed. The Brushes animation is especially nice: when you tap on it, eight specifically labeled brushes spring up from the bottom menu. Choosing one of those lets you use your finger to brush edits onto your picture.