Greater than the technical aspects involved with developing for different mobile platforms, the challenging job is understanding each platform, designing for its distinct characteristics, for its users, how they use and how they identify with their phones.
iOS, Android and Metro may have affordances that suite one more than another, but the designs should always respect the platform.
My Xbox LIVE and Track 8 are two examples of iOS apps that completely break from the Human Interface Guidelines (HIG), the design standards for all iOS applications. Whether it’s a boon to users, or if they pay a toll, it’s the developers who are responsible.
Users expect applications that work like the rest of the ones they already use, and they expect them to match the operating system choice they’ve made. The users have arguably made the single and most difficult choice: “What phone should I buy?”
Now more than ever before buying a phone is decision that touches on every part of a user’s life. Peoples’ phones are with them at home and at work. Their phones touch every part of their responsibilities and desires. Their phones also partially define them in social situations, and in intimate ones. This is the most appealing part about the mobile space to me, the richness of its elements, the touch points on so many different parts of life, and its built in connection with social. Building apps should start by understanding both the users, and the platform.
Its dangerous to break from this approach. Take for example Office 2011 for the Mac. The benefits of a Ribbon are harder to justify when users are given the responsibility of learning a new interaction model that’s the only one of its kind on the Mac.
When developer design a Metro app intended for iOS, the biggest opportunity lost is that it eliminates the option for using a skeuomorphic interface. While they aren’t everybody’s favourite characteristic of Apple design, removing them removes the possibility of designing intuitive applications, which is a fundamental part of what has made iOS and OS X so easy to adopt for people. Skeuomorphic applications look like the object they represent, and when users see them, they are afforded an intuitive understanding of what they do and how to use them.
When you include tablets into the equation, breaking from standard practices creates more problems. iPad applications are the most engaging when they take advantage of the iPad’s features like its big screen and the ability to use it in any orientation. Taking advantage of those two features requires reworking elements of your application and again, understanding the context the application will live in. This is the approach heralded by the HIG. Putting a Metro app on the iPad might create a great experience on its own, but it will be disjointed from the larger context.