We all expected Dark Mode in iOS 13, but according to this rumor from 9to5Mac, the next major version of iOS is also going to feature some major changes to windows and detachable sheets:
There are many changes coming to iPad with iOS 13, including the ability for apps to have multiple windows. Each window will also be able to contain sheets that are initially attached to a portion of the screen, but can be detached with a drag gesture, becoming a card that can be moved around freely, similar to what an open-source project called “PanelKit” could do.
We also get an answer to one of the questions Brent Simmons asked about split views:
Split Views on Marzipan apps based on iPad designs that run on the Mac will get the ability to be resized by dragging the divider and have their position reset when double-clicking the divider, like existing Split View apps on the Mac.
I hope that support for multiple windows maps over to macOS with Marzipan. We’ve been saying on Core Intuition that this WWDC is going to be special. Marzipan is the biggest shake-up to the Mac since the Carbon to Cocoa transition.