Apple Plans to Let Developers Release Universal Apps That Work Across iPhone, iPad, and Mac by 2021, SDK Coming This June

Apple aims to allow developers to release universal apps that work across iPhone, iPad, and Mac by 2021, according to a new report today by Bloomberg's Mark Gurman.

The ultimate goal of the multistep initiative, code-named "Marzipan," is by 2021 to help developers build an app once and have it work on the ‌iPhone‌, ‌iPad‌ and Mac computers, said people familiar with the effort. That should spur the creation of new software, increasing the utility of the company’s gadgets.

According to Gurman, Apple plans to let developers port ‌iPad‌ apps to Mac using a new software development kit that the company will release as early as June at WWDC. Apple previewed the apps plan, without disclosing the road map, at its developers conference last year.

Apple typically previews the next major versions of its iOS and macOS operating systems at WWDC in June, with beta versions of each platform available to developers and public testers until September, so it stands to reason that an SDK for universal apps should begin rolling out in the pre-release software.

Developers will still need to submit separate versions of the app to Apple's iOS and Mac App Stores, but the new kit will mean they don't have to write the underlying software code twice, said the people familiar with the plan. In 2020, Apple plans to expand the kit so ‌iPhone‌ applications can be converted into Mac apps in the same way.

The "Marzipan" project is considered to be one of the biggest changes on Apple's roadmap, although Apple's plans are said to be "fluid" and could be altered, according to Gurman's sources.

When the idea of universal apps was first rumored in 2017, early speculation suggested that they were a harbinger of Apple's plans to create a unified operating system for all of its devices, but those rumors appear to have been unfounded. Apple has already said it won't combine iOS and macOS into a single operating system.

The work on universal apps aligns with Apple's preparations to start transitioning some Macs to its own chips as early as 2020. Apple's initiative, reportedly code named "Kalamata," is part of an effort to make Macs, iPhones, and iPads work more similarly and seamlessly together. Apple Macs currently use Intel chips but Apple already designs its own A-series chips found in iPhones and iPads.

Apple is planning to hold its annual software conference from June 3 to June 7 in San Jose, California, based on permit filings uncovered by MacRumors.