SwiftUI
frameworksApple's declarative UI framework for building apps across all Apple platforms using Swift.
Pronunciation
Correct
swift-you-eye
/swɪft juː aɪ/
Each part is read as its initialism: 'Swift' + 'U' + 'I'. Apple uses this pattern in all official materials and WWDC sessions.
Source: developer.apple.com(official spec)