Kotlin & Android & Swift & Flutter & React Native

Kotlin & Android

https://www.runoob.com/kotlin/kotlin-tutorial.html

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Swift 5 & iOS 12

https://swift.org/about/
https://swift.org/documentation/
https://developer.apple.com/swift/

https://swift.org/blog/swift-5-released/
https://github.com/twostraws/whats-new-in-swift-5-0

https://www.whatsnewinswift.com/

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Flutter & React Native

https://flutter.dev/

https://facebook.github.io/react-native/docs/tutorial.html

Light ???