Delight your users with Flutter's built-in beautiful Material Design & Cupertino widgets. Quickly ship features with a focus on native end-user experiences. Install Flutter today. Null Safe Code. Multi-Platform. Web Stable. Hot Reload. Fast Development. Native Performance.
Flutter is not simply a Framework, it's a complete solution for building applications, it's SDK provides everything a developer needs in order to build a quality and performant user interface and includes pre-built widgets for both Material Desing (Android) as well as Cupertino (iOS). Flutter is the framework, but Dart is the actual programming language behind it, like Flutter, Dart is also an open-sourced product being developed by Google. Within its core, there is also a high-speed C++ compiler, the resulting combination allows for highly performant native experiences at 60 or even 120fps. Unlike React-Native, Flutter and Dart make use of the Skia C++ graphics engine which minimizes interactions with the host operating system and removed the need for any form of Bridge.
It depends on what you want to achieve and what are your project's business goals. Flutter is a really good framework for some things, but as all cross-platform technologies it also has limitations. You shouldn't consider it as a magic bullet for all your troubles.