1. Let translucent UI elements hint at the content behind them. Translucent elements—such as Control Center—provide context, help users see that more content is available, and can signal transience. In iOS, a translucent element blurs only the content directly behind it—giving the impression of looking through rice paper—it doesn’t blur the rest of the screen.
2. Choose dynamic type since people increase font size in settings often
3. Some iPads have split view or slide over and a good app uses auto layout to make sure their app doesn’t get messed up in this mode
4. More important content in top left less important in bottom right
5. Give tappable controls a hit target of about 44 x 44 points.