Text Size is one of my favorite Control Centre controls. It lets you quickly change the Dynamic Type size, of the whole system. But also, you can now specify a different setting per app. Also, check out Dark Mode, Magnifier, Sound Recognition...

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There are a ton of things to love about SwiftUI. But one of my favorites it's got to be the possibility of previewing Variants: the possibility of seeing your UI in dark/light modes, all dynamic type sizes, and orientations, side-by-side.
If, for some reason, you are creating a button from scratch, instead of relying on UIButton (perhaps you are adding a fancy micro interaction animation?), take into account that you’ll need to configure the button accessibility trait.
@azzoor has this great video with some advice on how to set up your device for testing accessibility and a ton of tips will get you testing effectively in no time. https://m.youtube.com/watch?v=Ca1H6wF348g&feature=youtu.be