SwiftUI is a user interface toolkit that allows developers to design and build apps across all Apple platforms with Swift. Introduced by Apple at WWDC 2019, it employs a declarative syntax, enabling developers to describe the desired UI and behavior, while SwiftUI manages the rest. This simplifies code and enhances readability, saving development time. SwiftUI integrates with the Combine framework for reactive and asynchronous programming, crucial for efficient data flow and updates.
A key feature of SwiftUI is its cross-platform compatibility, which allows developers to use a single codebase for iOS, macOS, watchOS, and tvOS apps. The framework also offers live previews in Xcode, enabling developers to see real-time changes to the app's views as they code. SwiftUI simplifies animations, gesture recognition, and data binding, enhancing the interactivity and user experience of applications. The SwiftUI framework itself is free to use, but development typically requires a Mac. While the framework is free, costs can arise from hiring SwiftUI developers, with salaries ranging from $70,000 to $170,000+ annually in the US, or freelance rates of $75 to $150 per hour. SwiftUI is available now, and is continuously evolving with updates and new features.