NSUserDefaults and Swift

Over the years there have been numerous posts, on many blogs, on integration of NSUserDefaults in Objective-C.

Nick offers a thorough introduction to NSUserDefaults, focusing on Swift.

Beyond saving user preferred default values, another use of NSUserDefaults:

“Using NSUserDefaults in combination with App Groups is the simplest way to share data between your app and any extensions it has, including WatchKit extensions.”