The iPhone is in high demand and has maintained a very strong, loyal customer base since it first came on the scene in 2007. One of the main reasons people find the iPhone so appealing is because of its desirable aesthetics and simple design. As a result, it’s important that the apps in Apple’s iTunes App Store also maintain a high-level of design and usability for consumers. To do so, developers must consider several main principles provided by Apple’s iOS Human Interface Guidelines, which can be broken down into simpler terms.
Developers must keep in mind application styles before even attempting to build an app. These are based on visual and behavioral characteristics, data model, and user experience. When it comes to the app development process, remember that ”When in doubt, keep it simple.” Also, ask yourself these few questions:
- What would be a user motivation to use your application?
- How should the user experience be when your app is opened?
- What is the goal/objective of the application?
- How should the information/ visuals be organized and displayed?
Great iOS apps fully embrace the basics of platform and human interface design, but they should also abide by a few other principles. To better understand this, it makes sense to dig into both the functional guidelines as well as platform characteristics provided by Apple. An app’s functional aspects are extremely important and the app should prove its worth for the following parameters:
- Apps cannot crash, or they will be immediately rejected
- Apps exhibiting bugs will be rejected due to lack of performance
- Apps that use non-public APIs and the ones reading or writing data outside their designated container area will be rejected
- Duplicate apps or very similar apps which are already in the App Store will be turned away
- Apps larger than 50MB in size can not be downloaded over cellular networks and thus, these apps are automatically prohibited by the App Store
Developers should also be aware of basic iOS platform characteristics before building an app. Keep in mind:
- The comfortable minimum size of a tappable UI element is 44 x 44 points. People will be turned off by low-quality visuals and no matter what size screen is being used, design is paramount.
- Device orientation switches between portrait and landscape, so iPad users should not be overlooked when developing and iPhone app (since all iPhone apps run on the iPad as well).
- Apps respond to gestures through Apple’s multi-touch interface. The table below describes each gesture a user can make in order to interact with their iOS device:
These guidelines are very important when submitting an app to be evaluated by Apple. There are over 700,000 apps in the App Store as of September 2012, which means there’s a high possibility that an app will be rejected unless it runs well and carries a unique purpose. Although I’ve only touched on a few topics of focus when it comes to the iOS Human Interface, this a good place to begin before diving into the coding process.