Making portable mobile applications have always been a crucial mainstay of the tech business but developing apps for multiple platforms has been an issue for quite a while. Apart from having to maintain and manage two teams such as one for Android and one for iOS, there’s always a gap between the applications developed as they are made by totally different teams. That is the thing which birth an idea to make cross-platform mobile applications.
There are many solutions available now but the right one is to create compiled apps which give you the exact performance of the real native application. Google's flutter and facebook's react native are the two contenders in this.
React Native is an open source framework released on GitHub that paved the way for uniting both the iOS and Android platform’s native APIs. However, Google’s Flutter has been a revolutionary move, which allows you to create Android and iOS highly responsive native apps at the same time.

Flutter vs React Native - A quick comparison

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Read more about the interesting war between two tech giants here:-https://www.bridge-global.com/blog/flutter-vs-react-native-war-of-tech-giants/