Respond to accessibility preferences. If your app uses UIKit to implement its user interface, text and interface elements automatically adapt to certain accessibility preferences, like bold text. Your app should also check and respond to accessibility preferences when appropriate, such as if the option to reduce motion is enabled. Apps implementing custom fonts should attempt to match the accessibility behavior of the system fonts.
Provide alternative text labels for images, icons, and interface elements. Alternative text labels describe what's onscreen but aren’t actually visible onscreen. VoiceOver speaks this text, making navigation easier for people with visual impairments.
Test your app with accessibility features. In addition to text and motion changes, accessibility options can change contrast and reduce transparency. Enable these settings and observe how your app will look and behave for people who enable these features.
Include closed captions and audio descriptions. Closed captions allow the deaf and hard-of-hearing to perceive spoken dialogue and other audible content in videos. Audio descriptions provide spoken narration of important video content for the visually impaired.
Use sufficient color contrast ratios. Insufficient contrast in your app makes content hard to read for everyone. An online color contrast calculator can help you accurately analyze the color contrast in your app, to ensure that it meets optimal standards. Strive for a minimum contrast ratio of 4.5:1, although 7:1 is preferred because it meets more stringent accessibility standards. For additional design guidance, see Color.
For information about the accessibility features of Apple TV, see tvOS Accessibility and UIKit Accessibility.