I was taking an in depth look at Auto Layout, constraints and stack views.
Auto Layout is a tool used to build adaptive user interfaces. With Auto Layout, you can set up rules or constraints to define how views will be laid out. Auto Layout should be used by developers when making applications to make their app responsive.
For example, to ensure the display is centered, horizontal and vertical constraints, best thought of as rules, should be set.
Stack views, keeps views arranged either vertically or horizontally. Once this is done, constraints can be set up on the stack view to make it centered. The proper use of these will facilitate the adaptability of your app, as far as how it is viewed, to every device.