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Chapter 1: Creating Killer iPhone Applications
Operational consistency
As with the Macintosh, users have a general sense of how applications work
on the iPhone. (The Windows OS has always been a bit less user friendly, if
you ask a typical Mac user.) One of the early appeals of the Macintosh was
how similarly all the applications worked. So Apple (no fools they) carried
over this similarity into the iPhone as well. The resulting success story sug-
gests the following word to the wise. . . .
A compelling iPhone user experience usually requires familiar iPhone inter-
face components offering standard functionality, such as searching and navi-
gating hierarchical sets of data. Use the iPhone standard behavior, gestures,
and metaphors in standard ways. For example, users tap a button to make
a selection and flick or drag to scroll a long list. iPhone users understand
these gestures because the built-in applications utilize them consistently.
Fortunately, staying consistent is easy to do on the iPhone; the frameworks at
your disposal have that behavior built in. This is not to say that you should
never extend the interface, especially if you’re blazing new trails or creating a
new game. For example, if you want to “unlock” something in your user inter-
face, why not use a pinch-open gesture, which adheres to the spirit if not the
letter of the law, spelling out how to use the “standard” gesture?
Making it obvious
Although simplicity is a definite design principle, great applications are really
about being easily understandable to the target user. If I’m designing a travel
application, it has to be simple enough for even an inexperienced traveler to
use. But if I’m designing an application for foreign-exchange trading, I don’t
have to make it simple enough for someone with no trading experience to
understand.
Keep the following points in mind as you develop an application:
✓ The main function of a good application is immediately apparent and
accessible to the users it’s intended for.
✓ The standard interface components also give cues to the users. Users
know, for example, to touch buttons and select items from table views
(as in the contact application).
✓ You can’t assume that users are so excited about your application that
they’re willing to invest lots of time in figuring it out.
Early Macintosh developers were aware of these principles. They knew that
users expected that they could rip off the shrink-wrap, put a floppy disk in
the machine (these were really early Macintosh developers), and do at least
something productive immediately. The technology has changed since then;
user attitudes, by and large, haven’t.
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