iPhoto for iOS is great. It’s innovative, comprehensive and immersive. But these myriads of features also come with a price: unfamiliarity.

It’s hard to be minimalistic and a Jack of all trade all at once. iPhoto for iOS has some never-before-seen editing features & UI conventions packed into a palm-to-tablet sized real estate. Clever the design is, not every function can be translated into visible UI metaphors, new elements must be introduced, and iPhoto has plenty of them.

The most impressive but less obvious feature is the double-tap-to-compare-similar-images. There’s the swipe-across to view the thumbnail grid, and the undocumented two-finger tap-and-hold loupe mode.

Then there’s the advanced white balance adjustment.

This marks the first time that I actually need to read the documentation to use an iOS app.

You can resort to the [help pages](http://www.apple.com/support/ios/iphoto/), but you don’t wanna miss reading his post to learn some hidden tricks.