The following chapters are more free-associative than the preceding ones, but no less practical. All three of the developers in this section have created successful iPhone apps: Smule's have topped the App Store on several occasions; Instapaper is a favorite of web addicts everywhere and its API features in popular apps like Tweetie and iReddit; and Toronto developer MarketCircle won a 2009 Apple Design Award (ADA) for its Mac app Billings 3, and is now working on an iPhone version of that app.

But in addition to winning approval from users and from Apple itself, these developers have also spent more time than most considering--and speaking out about--the peculiarities of the device and its ecosystem. Reading these chapters will allow you to spend more time coding and less time struggling with approval, updates, customer service, motivation, pricing, and sales. They'll also give you three design philosophies you can adapt, study or react against.

Marco Arment, lead developer of Tumblr and creator of Instapaper, is particularly deft at cutting through some of the so-called "common knowledge" sophistry that clouds the platform. Wang, who co-founded Smule, makers of hugely popular musical apps, shares his holistic ideas keeping inspiration and creativity central to the development process. And Brandon Walkin and Alykhan Jetha of MarketCircle discuss how they've successfully iterated through three versions of Billings and brought the final version mobile.

While we're feeling philosophical: why are the developers in this book developing for this platform, anyway? What can we learn from the iPhone itself? This chapter dives into those questions headlong, and ferrets out how small teams and slow deliberate timelines have fomented not only these developers' success, but Apple's.