The mother of all mobile app development frameworks.

When Google announced the Flutter beta version sometimes in 2018, some developers thought the this new framework was going too immature to be used for building mobile apps.
Fast-forward to 2020, and Flutter is now more popular than ReactNative according to Stack Overflow trends.

Flutter is the best solution for creating cross platform mobile apps. The SKIA library that powers it set it apart from alternatives like ReactNative(requires a JS bridge and native APIs can't be used directly), Xamarin(latest APIs from Google and Apple are not available), Cordova/ionic (outdated technology) and NativeScript(Typescript or JS has performance issues).

Flutter relies on Dart language, but you can add your Kotlin or Swift code to the application with ease. It's also interoperable with c/c++ libraries.

In addition, Flutter is a companion of the Fuchsia OS that is being developed by Google. More corporate entities and forward thinking developers are now building new apps using Flutter. Get on board and a trial will convince you.

A sample flutter app: https://play.google.com/store/apps/details?id=com.inspirati.foodforlife