The Apple WatchKit SDK site by Apple, (now called WatchOS) has released the Xcode with iOS SDK to build applications, Glances, and notifications for Apple Watch. With SDK development, clients could receive notifications directly to their watches targeted to their best interests. Besides Xcode, users have access to videos, guides, tutorials, and forums. Apple suggests that developers can build with the latest SDK while running the app on a previous OS. The reason why is because this particular setting is independent of the Base SDK build setting.