iOS 11 Design Principles Cheat Sheet by asolanes

Aesthetic integrity represents how well an app’s appearance and behavior integrate with its function. For example, an app that helps people perform a serious task can keep them focused by using subtle, unobtr­usive graphics, standard controls, and predic­table behaviors. On the other hand, an immersive app, such as a game, can deliver a captiv­ating appearance that promises fun and excite­ment, while encour­aging discovery.

A consistent app implements familiar standards and paradigms by using system­-pr­ovided interface elements, well-known icons, standard text styles, and uniform termin­ology. The app incorp­orates features and behaviors in ways people expect.

The direct manipu­lation of onscreen content engages people and facili­tates unders­tan­ding. Users experience direct manipu­lation when they rotate the device or use gestures to affect onscreen content. Through direct manipu­lation, they can see the immediate, visible results of their actions.

Feedback acknow­ledges actions and shows results to keep people informed. The built-in iOS apps provide percep­tible feedback in response to every user action. Intera­ctive elements are highli­ghted briefly when tapped, progress indicators commun­icate the status of long-r­unning operat­ions, and animation and sound help clarify the results of actions.

People learn more quickly when an app’s virtual objects and actions are metaphors for familiar experi­enc­es—­whether rooted in the real or digital world. Metaphors work well in iOS because people physically interact with the screen. They move views out of the way to expose content beneath. They drag and swipe content. They toggle switches, move sliders, and scroll through picker values. They even flick through pages of books and magazines.

Throughout iOS, people—not apps—are in control. An app can suggest a course of action or warn about dangerous conseq­uences, but it’s usually a mistake for the app to take over the decisi­on-­making. The best apps find the correct balance between enabling users and avoiding unwanted outcomes. An app can make people feel like they’re in control by keeping intera­ctive elements familiar and predic­table, confirming destru­ctive actions, and making it easy to cancel operat­ions, even when they’re already underway.