Apple has just made it easier to share documents, and much more, between mobile devices and computers. AirDrop has been expanded into a system that syncs files and communications between iOS and OS X, allowing you to switch off documents, mail, and even phone calls. With the new "Handoff" tool, an icon will let you swipe between, say, a Mac and iPad while writing a document, picking up editing in real time. But the new features go beyond that. Apple devices can also use proximity sensing to tell when you may want to finish a message from a computer instead of a mobile device, and your Mac or iPad can detect an iPhone and allow you to set up a mobile hotspot from it. When the network isn't in use, it will automatically disconnect. Handoff can be used with virtually all major Apple apps, including Safari, Maps, Pages, and Calendar, and third-party developers can build support into their apps.

Real-time editing across devices was already covered by Google Drive and various web apps — and iCloud Drive, announced earlier during the event, syncs documents across machines. But this system is a more native solution that goes beyond normal productivity tools, even turning your computer into a supplemental phone. The desktop iMessage service can now relay SMS messages through your iPhone to friends with, in Apple VP Craig Federighi's words, "inferior devices." It can even let users take or make a call from the desktop, effectively turning it into a speakerphone. This new tool is part of an overall convergence (Apple calls it "Continuity") of mobile and desktop operating systems, something evident in the iOS-inspired design of the latest version of OS X, Yosemite. Like everything else in Yosemite, it will be coming in the fall, with a public beta program this summer.