Apple has finally decided to implement the universal shopping. This means that an application that is available for iOS, iPadOS, tvOS and macOS you only buy it once and you can download it on all your devices. Until now, the App Store for portable devices was different from that for computers.
If for example (as is my case) you had bought Affinity Photo for your Mac, and then you wanted to use the iPad version, you had to buy it again as a different application. Now Apple offers the possibility to the developer to group the purchase in a joint multi platform. The "Adaptivity" application is an example of this new possibility.
One of the biggest challenges developers face when programming for Apple platforms today is the graphic design of applications. They must be adapted to all screen sizes available (for Android it's already crazy).
Most applications need to look good on an iPhone SE with its 4-inch screen, even the 12,9-inch iPad Pro. That's why many graphics-based applications, especially games, are for either iOS or iPadOS. It has more work to develop them for two platforms.
With CatalystSome applications also need to work well on the Mac. The application should work well in both a small window and a full window, taking into account the various screen resolutions of current Macs.
«Adaptability»Is an application that helps developers to view the applications that are being created on the different screens of all the Apple devices that exist today.
This tool has long been available for iOS and iPadOS and now available for macOS as well. Your Creator, Geoff Hackworth, wanted to take advantage of the novelty that Apple offers with universal purchases, and is available for iOS and macOS for 4,49 Euros, with a single purchase for the two platforms. Let's hope it sets the example.