I think you should give the Apple User Interface Guidelines a read.
Consistency in the interface allows people to transfer their knowledge and skills from one application to
another. A consistent application is not a slavish copy of other applications. Rather, it is an application that
takes advantage of the standards and paradigms people are comfortable with.
To determine whether an app follows the principle of consistency, think about these questions:
● Is the application consistent with iOS standards? Does it use system-provided controls, views, and icons
correctly? Does it incorporate device features in a reliable way?
● Is the application consistent within itself? Does text use uniform terminology and style? Do the same
icons always mean the same thing? Can people predict what will happen when they perform the same
action in different places? Do custom UI elements look and behave the same throughout the app?
● Within reason, is the application consistent with its earlier versions? Have the ter
Also Page 55,
Use UI Elements Consistently
People expect standard views and controls to look and behave consistently across applications.
Follow the recommended usages for standard user interface elements. In this way, users can depend on
their prior experience to help them as they learn to use your application. You also make it easy for your app
to look up-to-date and work correctly if iOS changes the look or behavior of these standard views or controls.
For an app that enables an immersive task, such as a game, it’s reasonable to create completely custom
This is because you’re creating a unique environment, and discovering how to control that
environment is an experience users expect in such applications.
Avoid radically changing the appearance of a control that performs a standard action. If you use unfamiliar
controls to perform standard actions, users will spend time discovering how to use them and will wonder
what, if anything, your controls do that the standard ones do not.
iOS makes available to you many of the standard buttons and icons used throughout the built-in applications.
For example, you can use the same Refresh, Organize, Trash, Reply, and Compose icons that Mail uses on
both iPhone and iPad.
To avoid confusing people, never use the standard buttons and icons to mean something else. Be sure
you understand the documented meaning of a standard button or icon; don’t rely on your interpretation of
its appearance. To learn more about using system-provided items, see “System-Provided Buttons and
Icons” (page 135).
In addition to the benefit of leveraging users’ prior experience, using system-provided buttons and icons
imparts two other substantial advantages:
● Decreased development time, because you don’t have to create custom art to represent standard