Federighi emphasizes that macOS will never merge with iOS, not even for a touch screen.
At WWDC a few days ago, Apple shared a tool for developers to efficiently transfer iOS apps to macOS, announcing the feature will be available for third-party developers by 2019. But we still have many doubts. Wired has published the interview of Craig Federighi, Apple’s software engineering supervisor, who gave specific answers about this transfer project.
Federighi expressed that this project was established two years ago mainly involved the update for UIkit, as Apple needed to make this iOS frame works for macOS. He also emphasized that it did not mean macOS would be able to run iOS App right after this, it is not automatic. Developers will need to do some extra programming.