If your organization has a mobile app, accessibility should be a design consideration from development to deployment. Laws like the Americans with Disabilities Act (ADA) prohibit discrimination on the basis of disability and the Department of Justice (DOJ) has interpreted this to extend to digital goods and services, including websites and apps. Mobile devices like phones and tablets come with unique access features and challenges like limited screen sizes, touch-based interfaces, changes in screen orientation, and more.
The World Wide Web Consortium (W3C)’s Web Accessibility Initiative (WAI) Web Content Accessibility Guidelines (WCAG) are the most widely-used standards on digital accessibility. The WAI also released a working draft specifically covering mobile design: Mobile Accessibility: How WCAG 2.0 and Other W3C/WAI Guidelines Apply to Mobile. It centers on WCAG’s four core accessibility principles, known as POUR: Perceivable, Operable, Understandable, and Robust. Read on for examples of accessible mobile app design approaches rooted in these principles.
Is your mobile app perceivable?
There are several aspects of mobile content delivery, like the smaller screen size, which impacts the way content is viewed by users. Designers can make content more accessible on mobile devices by minimizing the amount of information available on each screen and developing content that is responsive to all output types. Zoom and magnification options can also affect content readability.
Text contrast is another consideration. Content needs to be easily-distinguishable, meaning in part that content can be perceived against its background, and proper contrast helps achieve that. Because many people have color blindness and other differences in color perception, and because mobile devices are often used outdoors, using text that strongly contrasts with its background is very important. It should also be easy for users to change the orientation of their screens between portrait and landscape views. Apps should also offer multiple ways for users to enter data, including touch, speech, and on-screen or Bluetooth keyboards.
Is your mobile app operable?
When developing a mobile application, consider how the user will navigate and interact with the app. Position interactive elements like buttons where they can be easily reached, even when the device is held in different positions. It’s also important to support keyboard interfaces, which allow Bluetooth keyboards or alternative on-screen keyboards to operate devices.
Another consideration is the size and arrangement of interactive touch features — they should be big enough and widely spaced enough to allow for quicker selection (WCAG provides specific target size and spacing specifications). App designers should also remember that touchscreen gestures such as drawing with a finger on a screen are challenging for some users so alternative input modalities should be available. This is also true for manipulation gestures (tilting or shaking a device to achieve a desired result), which should only be provided as enhancements, not the only options for completing a task.
Is your mobile app understandable?
There are many ways to make your mobile app accessible and understandable for people with and without disabilities. For example, provide a consistent layout across multiple pages, and position the most important content up top, before a page scroll is required. Make it clear which elements are actionable or interactive by giving them distinctive features like a conventional button shape, color offset, or underlined and colored text for links. If an app offers custom touchscreen and device manipulation gestures, UX designers should make instructions and tutorials for these functions easily discoverable each time the functions are available (not just on the first usage).
Is your mobile app robust?
To ensure the robustness of your mobile app, W3C recommends setting the virtual keyboard to the type of data entry required. For example, if the user is asked to enter payment information, adjust the settings for the user so only payment-related data entry options are provided (a numeric keyboard for credit card numbers). People who use screen reading technology may find this change confusing so it may be helpful to notify the user of this change at some point in the process (for example, advising the user that required fields populate data specific virtual keyboards).
Apps should also offer multiple ways for users to enter data, including touch, speech, and on-screen or Bluetooth keyboards. And, to increase mobile app robustness, “Reduce the amount of text entry needed by providing select menus, radio buttons, and check boxes, or by automatically entering known information (for example, date, time, location),” WAI states.
Develop apps that support the characteristic properties of the platform. Features and functions vary depending on the device type and operating system. Designers should be aware of this and develop applications that complement the accessibility functions of the operating system. For example, designers should consider that iOS zoom screen functions generally require a three-finger tap, while Android zoom features can be launched with one finger.