MacOS Catalina's iPad apps for the Mac are here, but the story is just getting started

Catalyst has been slow to take off on MacOS 10.15, but here's a look at the state of tablet apps migrating to Apple's laptop and desktop computers.

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Alison DeNisco Rayome
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Apple unveiled Project Catalyst in June at WWDC.


Apple's efforts to bring iPad apps to the Mac are beginning to pay off, but there's still a long way to go before Mac users are able to find many of their favorite apps on their desktop the same way they do their iPhone or iPad. 

Apple first gave a sneak peek at Mac Catalyst -- formerly known as Project Catalyst and Marzipan -- at its 2018 WWDC conference. Catalyst was formally unveiled at WWDC 2019 in June as software that would make it possible for developers to move iPad apps to the Mac by simply "checking a box" in the development program Xcode. 

The news was met with enthusiasm and some wariness by developers, who had long wanted a way to make their apps accessible across Apple's different platforms -- particularly after watching the Mac ecosystem languish while iOS and iPadOS apps grew into the millions, despite MacOS still having more than 100 million active users

While early apps created for Mac with Catalina weren't well received by users, the release of MacOS Catalina brought several more to the Mac App Store that seem to have benefitted from more time in development. The technology remains in its infancy, but it has allowed smaller development shops who otherwise wouldn't have the resources to create Mac apps to do so with relative ease. 

"Our vision for Mac Catalyst was always to make it easier for any iPad app developer, big or small, to bring their app to the Mac," said Todd Benjamin, MacOS product marketing director. "This allows them to leverage one codebase and one development team. Mac Catalyst gives iPad app developers a huge head start and for many, an opportunity to expand their reach onto the Mac platform that they may not have had before. Not only is this great for developers, but it's also great for Mac users, who benefit with access to a whole new selection of great app experiences from iPad's vibrant ecosystem." 

Here's a look at where Catalyst stands now, and how the technology aims to improve the Mac experience for users and developers. 

Watch this: Apple is bringing iPad apps to your Mac

The Mac community

Many Mac developers and users have long felt neglected by Apple after the company's main focus shifted to the iPhone and iPad, particularly when it came to apps. 

Catalyst will help keep the Mac from falling behind on engineering bandwidth and features, said developer Steven Troughton-Smith. But its initial rollout was rocky at best: The first four apps created with the software and released by Apple itself on MacOS Mojave in 2018 -- News, Stocks, Voice Memos and Home -- were "rudimentary at best," CNET said at the time, and failed to take advantage of the Mac's full capabilities. While Apple software chief Craig Federighi told CNET that they would be improved, major changes have yet to come. 

With the official arrival of MacOS Catalina, however, more apps were added to Mac with Catalyst and they improved upon the first four. Podcasts in particular was modified with native Mac menus and looks similar to native Mac apps like Music, TV and Books. The new "Find My" app was another where Apple used Catalyst, and it's been generally well-received. Catalina launched with a couple dozen Catalyst apps from third-party developers. 

Some of the new third-party iPad apps to arrive on the Mac via Catalyst included Rosetta Stone, GoodNotes, Carrot Weather and Twitter. More than 30 are now curated in a section of the the Mac App store called "Apps You Love, Now on Mac." But generally, more than 100 Catalyst apps are mixed in with all the others in the Mac App Store, with no designation that they were created with Catalyst. Some of the most anticipated apps for Mac, including DC Universe and Asphalt 9: Legends, remain in development

Asphalt 9, a hugely popular free-to-play racing game, was delayed until later this year so its developers can further polish the experience. Once it's ready, the game's Mac version will allow players to sign into a single account across their Apple devices, to more easily switch between them and continue playing the same game, said Catalin Vasile, technical director at Gameloft Barcelona, the development studio behind Asphalt 9. The Mac setup also allows the game developers to push all of the details further while running at 60 frames per second without worrying about battery life, Vasile said. 

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Opening up the world of Mac 

The app PDF Viewer had a large codebase on iOS, but company founder and CEO Peter Steinberger was never able to make the business case to invest the resources in a Mac app -- until Catalyst came along. 

Steinberger's team spent about three months creating and optimizing the PDF Viewer app for Mac with Catalyst. Without it, the process would have taken about two to three years, he said. 

"It has us going much faster, and now we have a product that gets us in the Mac App Store," Steinberger said. "It's an extremely exciting technology and I'm sure this will bring a lot more apps to the Mac." 

Many other developers interviewed for this story -- particularly those working on small teams -- reported similar experiences. 

"We hadn't made the investment in a MacOS standalone app, but this just made it a no-brainer," said Greg Spils, vice president of product experience at Rosetta Stone. "We can have a MacOS app without developing yet another product that requires a full stack support." 


The Twitter app on MacOS Catalina. 


Users of the Post-it app had requested a desktop version, and Catalyst was a relatively easy way to make that happen, said Remi Kent, global brand director for Post-it and Scotch at 3M Company. 

"It took less than a day to get our iPad app running on Mac using Project Catalyst," Kent said. "That allowed for the team to spend a lot of time optimizing it for the desktop usage, making sure that the app user experience was excellent." 

Checking the box in Xcode -- the MacOS development environment -- does most of the heavy lifting to port an app from iPadOS to MacOS, allowing most developers to get a working version of their app up on Mac within a day. That box, however, is only the beginning, said Pontus Axelsson, founder and president of Bontouch, the developer of the Post-it app. 

"The first step is checking the box," Axelsson said. "Then you actually have something you can use, and then you can go ahead and spend as much time as you want making it a great desktop experience and optimizing it." 

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The development process

Optimizing apps for Mac means building in different mechanisms, like keyboard and mouse support, and considering how a larger screen changes your content. 

"The two are completely different platforms which users use differently. And so, the Catalyst development process was also about designing how the app would translate into a desktop experience," said Vidit Bhargava, designer of the app LookUp, who wrote extensively about his experience developing with Catalyst. "The user interface paradigms of a touchscreen don't always translate that well into a point-and-click device like a Mac. Therefore, it makes sense to think of these apps as MacOS apps first, instead of iOS apps running on MacOS." 

The iPad and MacOS apps for LookUp share code thanks to Catalyst, but not shared user interface, as that is tailored to each platform, Bhargava said. Once the basic app experience was ready, he worked on bringing MacOS-specific components like menu bars, touch bars, right-click menus, help tags, user guides and extensive keyboard shortcuts. "These are small bits that add up to providing an experience where the user feels at ease when using the app on MacOS," Bhargava said. 

For users, Catalyst has the potential to bring a new kind of app ecosystem to MacOS that will enable people to do more with their Macs, Bhargava said. The general experience of using Catalyst apps is also going to be much better than using a web app or services like Twitter and Jira, he added. 

"My key takeaway from Catalyst is that it's easy to create an app that works on MacOS," Bhargava said. "But designers and developers would still benefit from doing the work to provide a native MacOS experience."

Watch this: MacOS Catalina: 5 best things

Major challenges

While Catalyst opens the door to the Mac ecosystem for many iOS developers, it remains an imperfect passageway. 

One major issue raised by developers is a lack of clear documentation and guidance as to how to actually use Catalyst to make a Mac app, let alone a great one, Troughton-Smith said. 

Apple released several WWDC session videos to guide developers, which Kevin Reutter, developer of the Planny 3 app, said he found helpful. "But I hated that many APIs were renamed or weren't available or working within the first betas, for example CloudKit Sharing," Reutter said. "In Catalina beta 7 Apple even broke dark/light mode for me, and it didn't work for weeks." 

Some parts of Catalyst, such as the SceneKit framework for certain 3D apps, including one of Troughton-Smith's, shipped completely broken on older Macs. "As I personally am living on an older Mac, that's meant I have been unable to develop one of my apps at all for months, and I've heard a lot from other developers who have had blockers like that of one kind or another preventing them from making any progress on their app," he added. 

Beyond beta issues, there is currently no way to share purchases between the App Store and the Mac App Store, so users have to buy the same app twice to use it on both their iPad and Mac, which is confusing and inconvenient, Troughton-Smith said. 

"It prevents smaller developers from being able to share their subscription models between iOS and MacOS without the added complexity of running a service back-end and being liable for collecting user data under GDPR," he added. 

Of course, Catalyst isn't the only option for developers who want to build a Mac app. They can still do so from scratch using AppKit, or build one for multiple Apple platforms using the new SwiftUI

While many developers remain apprehensive about Catalyst, it remains the best option available, many said. 

"It's a great and easy way to simply bring iPad apps to the Mac," Reutter said. "They can be bad, but also really great. Like always, it depends on the developers. Many things could be easier and and improved from a developer's perspective, but I'm sure it will become better over time." 

Apple is taking developer feedback into account when it comes to improving Catalyst, Benjamin said. "For many of the early Mac Catalyst developers, it was their first time ever developing an app for the Mac, and it's amazing what they've been able to achieve in such a short time," he added. "We're learning a ton from these early adopters, and are planning additional resources and support to help them create amazing Mac experiences with Mac Catalyst."

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The future of Mac apps

Catalyst is likely one of the first steps on Apple's rumored roadmap that ultimately leads to a universal app model, and a shared App Store between iOS and Mac in the coming years, Troughton-Smith said. Developers will need user feedback to help navigate this path, he added.

"Catalyst is one of the biggest changes to the Mac since Mac OS X in 2001, and I think it paints a very different picture for the future of the Mac," Troughton-Smith said. It needs more attention from Apple, however, to ensure that it's possible for developers to use it to build strong Mac apps, he added. 

For MacOS, both Catalyst and SwiftUI -- Apple's new framework for its programming language, Swift -- represent different ways to approach the same idea: learn once, apply anywhere, Bhargava said. 

"Catalyst is a great way to bring the current iPad apps to MacOS without having to learn a completely new framework. SwiftUI is the future of developing interfaces for all platforms, be it iOS, MacOS, WatchOS or TVOS," Bhargava added. "It's less about bringing one app to another platform but more about writing apps for different platforms more efficiently." 

SwiftUI has just arrived in 2019, however, and it will take time for developers to warm up to it. Apple's current development frameworks for iOS, UIKit, and Mac, AppKit, likely won't be going away for some time, Bhargava said. 

"Catalyst is a great, long-overdue initiative to bring MacOS and iOS closer together, to help the platforms learn from each other," Troughton-Smith said. "I can clearly see it as the obvious path forward for any new apps I will be writing, despite its flaws."