The app is composed of a simple view that lets the user edit a text field and fill it with random text.
The (business) logic which consits of creating the text is defined by a protocol TextGenerator which the app implements through the RandomTextGenerator class. The idea is that if the business rules change over time, the implementation of the TextGenerator can just be swapped to a new class without modiying the view code.
Finally the View uses a simple ViewModel for the data & user interactions, assembled together by the static function static func assemble()