Apple’s Catalyst tools will let iPad apps port to Macs
With Catalyst, Apple says developers can spend most of their time and resources on building a single version of their apps to work on Apple mobile and desktop platforms. This could spur more app development on macOS, and could make using Apple's various devices feel more consistent. As some observers have speculated, it could also pave the way for Macs that run on custom ARM-based processors, similar to those that power Apple's iPhones and iPads, rather than the Intel processors that Macs have relied on for the last decade.
Catalyst, which was code-named Marzipan, isn't without detractors, who've argued that porting iOS apps to the Mac results in a lowest-common-denominator experience that fails to capitalize on the Mac's strengths.
That debate will be settled when we see the first wave of Catalyst apps for macOS.