https://thenextweb.com/offers/2019/10/24/ios-13-is-the-new-arena-for-all-the-best-app-designers-master-it-first-for-just-20/

TLDR: With The Complete iOS 13 and SwiftUI Developer Bundle, you’ll harness the newfound power of Apple’s brand newest mobile operating system for over 90% off. 

It’s only been in the wild for a few weeks, but if we know one thing about tech users, adoption of a new Apple operating system always moves fast. In fact, Apple confirms the latest iOS update, iOS 13, was already running on more than half of all iPhones just 26 days after its launch.