App developers targeting Apple's platforms currently need to create at least two versions of their apps. One is aimed at iOS while the other at macOS. However, by 2021 this may no longer be the case as Apple is thought to be aiming for a "one app fits all" solution.

As Bloomberg reports, Apple is planning a multistep initiative which is being called "Marzipan." Expected to be in place by 2021, it would allow a developer to focus on creating one version of their app targeted at Apple's platforms. Deploying it to iPhone, iPad, and Mac devices would be handled automatically by the Marzipan system, which would take the form of a software development kit (SDK) provided by Apple.

The thinking is, by removing the need to create multiple versions of the same app, developers will be encouraged to release across all three platforms. Apple benefits because it gets a wider choice of apps across both its portable and desktop hardware, which in turn should bring a boost in app revenue. It should also boost hardware sales if that hardware can do more through more apps being available.

The same is true of subscriptions, with apps offered on a subscription basis being better value for money to consumers who can access the content across all their Apple devices rather than being limited to just their iPhone or Mac, for example.

The first stage of the Marzipan initiative is expected to arrive this summer when Apple releases a new SDK allowing iPad apps to be ported to Mac. The apps will still need to be submitted separately to each app store, but by 2021 that step should disappear. In 2020, iPhone apps will be incorporated into the SDK for Mac ports.

By removing the headache of porting from iOS to macOS, Apple no longer needs to tackle the question of whether it ultimately intends to combine the two operating systems into one. If it does, developers won't mind if they are already used to automatic conversions as nothing will change. This move should also make it easier for Apple to move to ARM chips inside its Mac hardware if that ever becomes a viable solution.