SwiftUI. I think Apple will put a lot of effort into it to be on the same level with UIKit. SwiftUI makes developing UI easier because it is declarative just like React Native and it takes less time to build your typical CRUD app on the apple platform.
Even though it’s extremely promising, I think it’s too early to start learning it, as you won’t be able to use in production for the next couple years because of the lack of backward compatibility.
