With so many folks using iPhone and iPad cameras, there is a desperate need to teach people the fundamentals of photography. I've looked at several apps that provide tutorials and some are excellent, while others are just not that helpful.
The Great Photo App (US$2.99) has some good ideas, but the presentation is flawed. Navigating the app is a challenge, the app is saddled with an inconsistent interface, and the entire style is condescending in places.
The app teaches topics like exposure, what ISO settings do, white balance, depth of field and more. The app features static pages, and then adds interactive demonstrations. For example, one describes how shutter speed choices can give you sharp pictures or a blur, the latter being useful if you are shooting moving water. These animated demonstrations are the best part of the app.
Navigation is the worst part. At times, you are told to tap on a checkmark in the upper right of a lesson, but no checkmark appears until you go back a page. There are additional lessons on things like location and light, but they need to be downloaded. Although the app says the lessons are free, it immediately asks for your App Store password. That's going to confuse a lot of users, most of whom will believe that they're getting nicked for an in-app purchase. And some of the lessons do require an in-app purchase, like a $0.99 purchase for Studio Portraits.