The App Design Guidelines have been updated to improve clarity on high quality app experiences.
In the app navigation section, it is now mandatory to use App Bridge’s Navigation Menu to integrate with the Shopify admin navigation experience if your app has different sections.
The existing requirement in the responsive grid section that apps must have responsive layouts for all device sizes has been moved to a callout card to make it more noticeable.
The wording of one callout card in the single-column layout section has been updated to make it clear that tables should only use the full width page if they have enough columns to require the extra space. Otherwise, they should use normal width pages.