Tapworthy by Josh Clark
O’Reilly Media, $39.99
How is an iPhone app different from any other program? The mobile platform means that users often have only short periods of time in which to work; to be successful, your app must be intuitive and easy to use. Josh Clark breaks down mobile apps into three purposes: microtasking (user wants to accomplish a quick task), local (user wants to accomplish something based on his location) and bored (user wants to be entertained).
A large part of designing programs for the iPhone, of course, is accommodating its unique physical design. Partially, this means designing for thumbs: how can you make your app easy to use for someone who is using it with one hand? Apple has determined the width of a thumb to be 44 pixels, and tends to make their buttons at least 44 pixels in at least one dimension; Josh recommends that you do likewise. Other considerations include icon placement; controls, for example, tend to be placed at the bottom of the screen where they’re easy to reach, while information (and dangerous controls) end up at the top, where they are inconvenient to touch.
The book covers different navigational structures, making your app unique, interruptions, and a number of other topics that make your app’s interface fade away so the user can focus on content. Make no mistake, this is not a programming book; it focuses entirely on the design of the application and involves no code whatsoever. I wouldn’t call this a particularly entertaining book, but if you want to make usable apps, it’s worth a read.