Complications in the watch making industry are added features to the movement of a watch beyond simply telling the hour and minutes. The Apple Watch, of course, features a selection of software-based Complications allowing you to put stuff like Activity rings, the weather, stocks, the latest sports scores and more right on your watch face.
With watchOS 2, Apple began permitting third-party complications on watch faces. To tell learn more about how third-party Complications work in watchOS 2, I took iCandi Apps' awesome stargazing app called Night Sky for a spin.