According to statistics, Flutter is the youngest and most popular cross-platform app development framework. But it is not the only cross-platform solution available on the market.
The greatest competition for the Flutter framework is React Native based on JavaScript. Cordova, Ionic, and Xamarin also have fans, but their market share is dropping. Other cross-platform technologies include Unity, NativeScript, PhoneGap, Kotlin Multiplatform, Apache Flex, Kendo UI, Kivy, and many more.
Nevertheless, companies tend to choose Flutter app development due to its popularity, versatility, and flexibility.