A new report from Bloomberg's Mark Gurman suggests that Apple is serious about combining apps across the iOS and macOS App Stores. The iPhone maker is reportedly planning on expanding Project Marzipan, a multistep initiative that will allow developers to create one app that works across iPhone, iPad, and Mac devices. Apple may reveal the first steps of this program as early as June 2019 at its annual Worldwide Developers Conference.

We first heard about Marzipan back in 2017, but this is the first hint of Apple's tentative schedule for its rollout and application. The company may debut an SDK later this year that will allow developers to port iPad apps to Mac computers. While developers will still have to submit two separate apps to the iOS App Store and the Mac App Store, the SDK reportedly makes it so developers only have to write the underlying code once.

By next year, Apple plans to expand the SDK to include iPhone apps, meaning developers could port iPhone apps to Macs in the same way. By 2021, developers may be able to merge iPhone, iPad, and Mac apps, creating one application that works across all of those Apple devices (what the report calls a "single binary"). At this stage, developers will not have to submit multiple versions of apps to different app stores—and Apple may be able to merge its separate stores into one all-encompassing app store.

According to "people familiar with the effort," Apple could change its plans at any time. Reportedly, one of the most difficult parts of the program is porting iPhone apps to Mac because of the screen-size discrepancy between the two types of devices.

While developers haven't had access to anything Marzipan-related at this point, Apple itself tested the idea in macOS Mojave. It brought a few traditional iOS apps—Home, News, Stocks, and Voice Memos—to Macs, so users got a glimpse of how such a transition would look. The final programs unsurprisingly look like a mash-up of Mac apps and iPad apps working in landscape mode, with support for Mac-specific controls like scrolling, right-clicks, the Touch Bar, and more.

Rolling out Marzipan, even if it takes longer than expected, will be beneficial to both developers and Apple as a whole. Developers' lives will be made easier once they only have to submit one version of their apps and have them work across Apple's most-used devices. While the iOS App Store is immensely popular, the Mac App Store is less so, partially because some developers have only made their apps available on Apple's mobile devices.

The move makes sense for Apple as the company shifts to focus more on services. Combining app stores and making apps work seamlessly across its mobile devices and computers will likely increase app downloads and sales overall. The future App Store with Marzipan, along with other services like iCloud, Apple Music, and the company's forthcoming TV streaming service , will contribute to Apple's goal of growing its services business (which hit $10 billion in revenue at the end of the 2018 fiscal year).

In addition to the first public notes on Marzipan, Apple may be considering a product announcement for WWDC in June. Bloomberg's report suggests the company may debut a new version of the Mac Pro in June, but that hasn't been confirmed. WWDC isn't the show for product launches, but Apple may reveal a new version of the Mac Pro and tease a release date for later in the year.