For apps that don’t require iPad-only features, the best way to ensure that your app will work well on a Mac is to make sure it works well on iPad. In particular, your app should:
* Support multitasking. Apps that do a good job scaling the interface to support Split View, Slide Over, and Picture in Picture approach the ultimate goal of supporting the extensive window resizability that Mac users expect.
* Support drag and drop. When you support drag and drop in your iPad app, you get the same support on the Mac for free.
* Respond to keyboard shortcuts, including common macOS shortcuts. Even though a keyboard may not always be available to your iPad app, both iOS and macOS users appreciate using keyboard shortcuts to streamline their interaction with your app.

Before You Start

A successful Mac version should be designed around desktop work patterns rather than treated as a scaled tablet interface. Begin by observing the tasks users keep open for long periods and decide how windows, resizing, and multitasking should support them. Then audit every important action for pointer precision, keyboard access, focus behavior, and command discoverability. Review information density and typography at typical viewing distances, and make common commands available through established macOS locations such as menus and contextual actions. Finally, test the app with large and small windows, keyboard-only navigation, accessibility settings, and real user workflows. The goal is behavioral fit with macOS, while preserving the product's underlying concepts and data.

Adapting a Touch-First App for macOS

University of Michigan - Ann Arbor

IOS - Human Interface Guidelines are "software development documents which offer application developers a set of recommendations." Their goal is to improve the user experience by making more intuitive and consistent application interfaces. 

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