Najjar, L. (2009). iPhone user interface design considerations.
Submitted to TandemSeven.com Insights Blog.
iPhone User Interface Design Considerations
Lawrence Najjar
The Apple iPhone is a powerful smartphone that is being used increasingly to improve the productivity of
mobile workers. To design simple, successful iPhone enterprise app user interfaces, keep in mind the unique
attributes of the iPhone.
- Small screen - The resolution of the iPhone is 480 x 320 pixels. This is large for a phone, but small
compared to a personal computer. Resist the temptation to jam in many user interface controls. They will
make your app unattractive and hard to use. Instead, limit the number of controls by limiting the focus of
your app. Break a single complex app into two or more apps with very different functions.
- One screen at a time - Except for some dialog windows, users can see only one app screen at a time. This
design style differs from the multiple simultaneous windows familiar to your users on their computers. In an
iPhone app, separate the major function into selectable tasks and allow users to move sequentially forward and
backward through the task screens. Design so that users drill down and sequence across.
- One app at a time - The iPhone can run only one app at a time. When users change apps, answer a phone
call, check their calendars, or send an e-mail, the current app closes automatically. Your app must save
user-entered data immediately, show the saved data the next time users open the app, and close gracefully
from any screen. Also, your app doesn't need a "Quit" button. iPhone users close your app by simply going
somewhere else on their iPhones.
- Minimal settings - Standard iPhone settings, such as display brightness and Wi-Fi access, are available
only in the pre-installed iPhone "Settings" app. If users are in your app and want to change iPhone
settings (such as changing display brightness for a flashlight app), they must open the "Settings" app, which
automatically closes your app. Minimize user frustration by minimizing the need for users to change standard
iPhone settings for your app.
- No training - The strongest asset of the iPhone is its ease of use. The simple user interface usually
allows users to get their tasks done without training or reading online Help. Users expect to open an app
and use it immediately. So, analyze your users - their needs, priorities, jargon, tasks steps - and design
a very simple, intuitive user interface that allows users to operate your app without training or Help.
- Hidden user input techniques - The iPhone allows users to perform multi-touch gestures (double tap, touch
and hold, drag, flick, swipe, pinch open, pinch close), tilt the phone, and shake the phone to make
inputs. These innovative, often hidden, user input techniques replace text and other displayed iPhone user
interface controls to make games and utilities more fun and entertaining. However, these hidden user input
techniques can make it difficult for mobile workers to figure out how to get their tasks done. Especially in
enterprise apps, use the familiar, standard, visual, iPhone user interface controls. Always display obvious
controls for your apps.
By taking into account these iPhone user interface attributes, you can design simpler, more effective,
easier-to-use apps for your users.
References
Apple, Inc. (2009, March 4). iPhone user interface guidelines: User experience. Retrieved
from http://developer.apple.com/iPhone/library/documentation/UserExperience/Conceptual/MobileHIG/Introduction/Introduction.html