Custom complications on watchOS 2: Explained
"Complications" is a term used to describe anything on a watch face that goes beyond telling the time. Calendar was the first Apple Watch complication that showed time keeping beyond what even a mechanical or digital watch could do. Now, with watchOS 2, Apple is letting third-party App Store apps in on the complications game with a framework called ClockKit. And in so doing, they're opening us up to something bigger and brighter—the future of the computational watch.
Full story from the iMore Blog...