Gruber: Apple's Cross-Platform App Support to Debut in 2019, Not 2018


macrumors bot
Original poster
Apr 12, 2001

Rumored cross-platform functionality that will allow Macs to run iPhone and iPad apps is planned for macOS 10.15 and iOS 13 rather than macOS 10.14 and iOS 12, according to well-known Apple journalist John Gruber.

Gruber shared the tidbit in a blog post covering "scuttlebutt" he's heard about the cross-platform UI project, which he says is indeed in the works at Apple.

News of support for universal apps able to run on iPhone, iPad, and Mac was first shared by Bloomberg's Mark Gurman in December. At the time, Gurman said Apple would introduce the functionality in iOS 12 and macOS 10.14, with an announcement likely to happen at the Worldwide Developer's Conference in June.

Gurman and Axios' Ina Fried later confirmed in January that the combined app framework was on the table for 2018 despite other planned iOS 12 and macOS 10.14 features being pushed back, but Gruber says he's "nearly certain" it's a 2019 project for macOS 10.15 and iOS 13, which could also be part of an updated UI for iOS said to be coming next year. "I would set your expectations accordingly for this year's WWDC," he writes.

According to Gruber, from what he's heard through first and second-hand sources, Apple appears to be working on declarative control APIs for iOS and macOS, which suggests Apple wants to make it easy for developers to create modern cross-platform user interfaces. Gruber's info is not as definitive as outright support for cross-platform iOS and macOS apps as has been previously reported, but it is an indication that Apple is working towards that goal.
There's nothing inherently cross-platform about a declarative control API. But it makes sense that if Apple believes that (a) iOS and MacOS should have declarative control APIs, and (b) they should address the problem of abstracting the API differences between UIKit (iOS) and AppKit (MacOS), that they would tackle them at the same time. Or perhaps the logic is simply that if they're going to create a cross-platform UI framework, the basis for that framework should be a declarative user interface.
It's not clear who is correct on the timing of the universal app project given the conflicting information, but we don't have long to wait to find out. macOS 10.14 and iOS 12 will be introduced at the keynote event of the Worldwide Developers Conference, which is set to take place on June 4.

Gruber's full writeup with additional details on the project can be found over at Daring Fireball.

Article Link: Gruber: Apple's Cross-Platform App Support to Debut in 2019, Not 2018


macrumors 68000
Feb 13, 2005
Coming from Gruber, this is obviously a planned "fake leak" blessed by Apple. Apple giving us the heads up that cross platform apps are still a ways away.
At most, it is another year away, but it could still be on the slate for June. At this point, it is only a matter of time.


macrumors 68000
Sep 7, 2004
Salt Lake
I think it would be great to announce and talk about development, giving developers a little over a year to work on apps. Giving some maturity to availability for 2019 os releases.

But that might be too optimistic. Marzipan and ARM in the same WWDC might be too much.


macrumors 68030
Apr 2, 2007
The only reason I want this feature is so I can use Homekit on my Mac. An App that is sorely missing. Though I'm sure for it to function would require more than just porting the Homekit app over, there is likely a lot of underlying dependencies woven throughout the iOS operating system that they would need to put in macOS as-well.

But hey, one can dream.


Feb 9, 2003
i think this new timing for cross-platform capability and the expected timing for a new MacBook Air is related.


macrumors 6502
Jun 9, 2017
I hope Apple takes their time and gets this right. We don't need another repeat of macOS 10.13 and iOS 11.

But this will be huge if Apple gets it right. Another differentiator between Apple and Windows, Android, Chrome OS, etc.
Am I the only one that doesn’t see how this can work? I don’t understand - you would have to implement so much UI and logic for each platform that apps will become bloated, no? You can’t simply scale apps for iPhone/iPad to Mac size, they wouldn’t look right. Not to mention touch vs. cursor input are used totally differently. Similarly, while the idea of layered pages swiping back/forth works for iOS, I don’t think it does for Mac.


macrumors Core
Nov 14, 2011
So Ming-Chi Kuo will stop reporting on Apple news, and now Mark Gurman's story may not have been accurate?

It's a sad day for Apple rumors :(
Gurman has sources but he’s not very good at interpreting what things mean or connecting the right dots. He thought Marzipan meant one OS. Gruber and others were always skeptical.


macrumors 6502
Jul 26, 2005
My concern about the cross platform is that this would be a nice excuse for app developers to significantly increase app price. Many will be angry!


macrumors 68000
Apr 10, 2007
I just hope this doesn't have a negative impact on the desktop apps. But I'd LOVE to run iOS apps on my computer.
  • Like
Reactions: PlayUltimate