UI

Flutter

Flutter apps look as good on the up-to-date operating systems as they do on older versions. Since they only have one codebase, the apps look and behave similarly across iOS and Android – but thanks to Material Design and Cupertino widgets, they can also imitate the platform design itself. How’s that possible? Flutter contains two sets of widgets which conform to specific design languages: Material Design widgets implement Google’s design language of the same name; Cupertino widgets imitate Apple’s iOS design. This means that your Flutter app will look and behave naturally on each platform, imitating their native components.

React Native

Application components look just like native ones (e.g. a button on an iOS device looks just like a native iOS button, and the same on Android). The fact React Native uses native components under the hood should give you confidence that, after any OS UI update, your app’s components will be instantly upgraded as well. That said, this can break the app’s UI but it happens very rarely. If you want your app to look near-identical across platforms – as well as on older versions of an operating system (as Flutter achieves) – then consider using third-party libraries (like this one). They will enable you to use Material Design components, in place of native ones.