An alternative layout for large font sizes can be provided with Auto Layout by having three sets of constraints (common, default constraints, and alternative constraints) and activate/deactivate them depending on the content size category.

You don't have to offer an alternative layout just for the accessibility category. You can actually compare content size categories. So you could tweak the UI already for anything equal to or larger than .extraExtraLarge, for example.

With accessibilityRepresentation(representation:), you can create a custom component and it can be perceived by assistive technologies as the view you pass as representation. No need to manually configure accessibility attributes. It is one of the most interesting additions to SwiftUI to help you develop accessible UI components. If your custom component behaves similarly to a native one, this is the way to go. https://developer.apple.com/documentation/swiftui/view/accessibilityrepresentation(representation:)

Too much data can overwhelm users. Very little is an incomplete experience. It is hard to find a balance on verbosity and the users may have different preferences. To help with this issue, the AXCustomContent APIs let you mark data as optional.

Love this feature! Yahoo released the possibility to explore charts with audio, in the finance app, when using screen readers in 2019. You can do now something very similar since iOS 15. https://coolblindtech.com/yahoo-finance-app-makes-charts-accessible-to-blind-and-partially-sighted-users/ You can move your finger in the x-axes, and it will play a sound with a different pitch depending on the data in the y-axes, making it easier to identify trends in the graphs. You need to conform to the AXChart protocol by implementing the accessibilityChartDescriptor property. Documentation: https://developer.apple.com/documentation/accessibility/audio-graphs WWDC21 session: https://developer.apple.com/videos/play/wwdc2021/10122/

If you need to send announcement notifications that can step into each other, they will by default, interrupt ongoing announcements. But you can pass attributed strings as parameters too, letting you specify announcements to be queued.

Potential benefits from grouping logical pieces of information and moving buttons to custom actions: reduce redundancy (by removing repetitive controls) and reduce cognitive load (by making easier to know what item will be affected by each action)

To capture the gesture, you can override the accessibilityPerformEscape() function. In there you can dismiss your view, and return true if you could successfully handle it. https://developer.apple.com/documentation/objectivec/nsobject-swift.class/accessibilityperformescape()

Color contrast between text and background is very important for perceivability. As colors come closer to each other, they’re more difficult to distinguish. Notice that colors that work well with big font sizes may not for smaller text.

Since iOS 14, you can get a human readable localised name for a UIColor, with a very useful property called accessibilityName, that you can use in accessibility attributes like labels or values. How cool is that? https://developer.apple.com/documentation/uikit/uicolor/accessibilityname

Guidelines from Apple: Begin with a verb that explains the results of the action. Avoid using the imperative form of a verb because that can make it sound like a command. Don’t include the action type. Don’t include the control. https://developer.apple.com/documentation/objectivec/nsobject-swift.class/accessibilityhint

When implementing a UISlider, it is a good idea to consider how much the slider value should change when swiping up/down to adjust it. It might not always make sense to do it in 10% increments, which is the default behaviour. Could be because the value at those intervals doesn't make sense, or feel random, or because it wouldn't provide the user with a fine enough control being able to go through the whole slider in just 10 swipes. It user will still be able to adjust the slider to any value by double tapping and holding and then moving the finger left or right, bypassing VoiceOver gestures. VoiceOver announces the new value as it changes.