Some iOS apps come with a welcome screen that allows you to swipe through several pages and then lets you use the app. Usually they include a page control at the bottom to show progress of viewing the pages.
Is there a popular or standard library that is providing this functionality?
Its quite simple,
Create a ViewController named
UIScrollView on the XIB, and load all the welcome images.
UIScrollView delegate methods, and determine that you scrolled to the last page.
When you reach last page, hide the whole pagecontrol, and scrollview and show a Welcome Screen with Start option.
On touching start option, change the window.rootViewController to your actual Home screen. And too save in UserDefaults that you have shown the Welcome Screen.
window.rootViewController should be
WelcomeScreen if you haven't shown it before.
The above should be the logic to implement what you are looking for.
Hope it helps.