Like categories in Objective-C, extensions in Swift give you the opportunity to add functionality to a type. This is not only possible for your own types, but also for types for which you don’t have access to the source code.
iOS is a very secure operating systems. One reason for this is that iOS apps can’t just be installed on every device as you want to – instead there are certain distribution ways you can choose from.
The best iOS development links from June 2017.