剋裏斯·史蒂文森（Chris Stevens）是Alice for the iPad的設計師，這款應用軟件曾經衝到過iPad應用商店（App Store）的首位並從那以後都賣得很好。Alice for the iPad在全世界範圍內超過50萬颱iPad上被安裝，並且這個數字還在不斷增加中。Gizmodo網站（美國科技博客網站）說這款應用是“到目前為止最聰明的iPad圖書”，英國BBC廣播公司說她是“未來數字閱讀的驚鴻一瞥”。Alice for the iPad還曾在《奧普拉·溫弗瑞秀》（美國脫口秀女王奧普拉·溫弗瑞製作並主持的節目）上亮相，奧普拉對聽眾說這款軟件“將改變孩子們的學習方式”。

剋裏斯曾經是《每日電訊》報（The Daily Telegraph）的科技專欄作者，後來他為《時代》（The Times）撰稿。他還為CNET齣品和導演過頗受歡迎的新鮮小展覽——“空間泡泡”（Space Bubble）。除瞭撰稿之外，剋裏斯還是一名插畫師，一位劇作傢。他曾經為華納兄弟（Warner Bros）、EMAP媒體公司以及《連綫》（Wired，美國科技雜誌）都工作過。剋裏斯曾經作為記者獲得過“衛報傳媒奬”（Guardian Media Award）。

現在，剋裏斯經營著Atomic Antelope公司，就是創造齣瞭Alice for the iPad的齣版公司。他直接和位於倫敦、紐約、東京的作者們一起創作新的圖書。

Get in the game of developing successful apps for the iPad Designing for the iPad presents unique challenges for developers and requires an entirely different mindset of elements to consider when creating apps. Written by a highly successful iPad software developer, this book teaches you how to think about the creation process differently when designing iPad apps and escorts you through the process of building applications that have the best chance for success. You'll learn how to take advantage of the iPad's exciting new features and tackle an array of new design challenges so that you can make your app look spectacular, work intuitively, and sell, sell, sell! Bestselling iPad app developer Chris Stevens shares insight and tips for creating a unique and sellable iPad app Walks you through sketching out an app, refining ideas, prototyping designs, organizing a collaborative project, and more Highlights new code frameworks and discusses interface design choices Offers insider advice on using the latest coding options to make your app a surefire success Details iPad design philosophies, the difference between industrial and retail apps, and ways to design for multiple screen orientations Designing for the iPad escorts you through the steps of developing apps for the iPad, from pencil sketch all the way through to the iPad App Store.

From the Author: The Top Three Reasons Why iPad Apps Fail, and How You Can Succeed

Design Apps for Fingers The App Wasn’t Really Designed for Fingers

This is the number one reason why an iPad app will be laid out on the mortuary table. The iPad is operated by fingers, and human fingers are nothing like a mouse and pointer. If you want to ship half-a-million iPad apps, like Alice for the iPad, you must not design your touch interfaces like you design mouse interfaces. Don’t be a Photoshop jockey, get out there and physically test your app designs on the iPad hardware from the point you make your very first pencil sketch. Touch-screens have almost nothing in common with the desktop computer paradigm, but you wouldn’t know it judging by some of the monstrosities on the app store. The mouse and pointer interface that most of us grew up with is a system of “indirect manipulation” -- this means that the user’s hand operates a mouse, which then moves a pointer, which then presses a button, or moves a window etc. However, the iPad uses a system of direct manipulation -- your hand directly touches the object it’s interacting with.

This small shift in interaction from indirect to direct-manipulation raises all kinds of issues for the designer. Now that objects can be manipulated directly, user’s hands can obscure parts of the scene. There is also the need for target areas with greater tolerance because the human finger is a podgy sausage of flesh, not a pixel-specific arrow. While the mouse pointer is pixel-specific, the human finger is amorphous. But this is not to say that the finger is any less powerful. In fact, with good interface design, the finger can be made infinitely more versatile than any mouse pointer. Sadly, many iPad designers have made the mistake of assuming that their knowledge of desktop computer user-interface design will apply to creating iPad apps. If you do this, you’ll end up making apps that aren’t really designed for touch. You can avoid the problem by testing and retesting your designs on actual iPad devices.

It Offers Too Many Options

Don’t offer choices to your users; make decisions for them. There is a popular capitalist mythology that assumes that the more choices you offer a customer, the more they will enjoy their experience. This might be true when you pick toppings in an ice cream parlour, but in the world of iPad apps, too much choice will kill you. Psychologists have found that the more options you present a consumer with, the more time it takes them to make a decision. But you won’t just slow down your users by offering lots of settings and choices, you’ll create a state of doubt in their mind. For every option that is available, you sow in their minds the unsettling possibility that an alternative option was potentially a better choice. Settings and choices are also often an excuse for bad design. If you are tempted to provide an iPad user with an option, consider picking the best choice for them instead and removing the option. The iPad is no place for nested menus or multiple settings -- not only is screen real-estate limited, but you’re probably packing too much functionality into your app if you need lots of buttons and settings.

It’s Hard to Explain

If you can’t explain your app idea less than ten words, then forget it, you’ve already lost. In the trench warfare of the app store only the clear and concise survive. The best iPad apps tend to do one task and do it well. If a customer cannot grasp the purpose of your app almost instantly, then it will spiral down the drain of the App Store, never to be seen again. Make it dangerously obvious what your app does, and shout about it. Before you write a single line of code or make a single sketch, have a long hard think about whether anyone will understand what it is you’re selling. You might have the greatest idea in the world on paper, but if the story of your app is not clear and compelling, nobody will share it and nobody will buy your app. Avoid this by discarding ideas that require a complex story to explain.

Don’t sell features, sell the story of the features: how will people actually use your app? When Apple launched Facetime, they didn’t ramble on about the resolution of the video or the specifications of the VOIP technology behind it, they focused purely on family members calling each other and sharing news in a heartwarming fiesta of emotion. People in real situations make strong, easy-to-explain stories but spec sheets are meaningless to the majority of consumers. To win the iPad goldrush, you need to explain the emotional story to the majority of customers, don’t try and sell the technical story to spec sheet fetishists -- they’re a tiny market. The paradox is that to make an iPad app simple is actually very hard, but you can do it!