Flutter is an open-source UI Software Development kit created by Google using an Apache license. It is an open-source multi-platform single code base. Used to develop applications from web browsers to OS like Fuchsia, Android, iOS, Linux, macOS, and Windows. It's also in the top ten most popular projects on GitHub. Flutter was first released by Google in 2015 supporting Android devices to render consistently at 120 frames per second and soon later supporting iOS. In 2021 Google released Flutter 2 supporting Windows, macOS, and Linux operating systems. Flutter emerged in the embedded world as an alternative to other UI frameworks like LVGL or Qt. The main advantages are free and open source against commercial license; declarative UI approach against procedural UI approach meaning a more expressive and flexible approach; hot reload and hot restart against rebuild and redeploy making work less time-consuming; large and active open source community. This talk will give an overview of these topics, starting from the integration in the OS build system like Buildroot and Yocto, showing the development environment and the differences between the languages C++/QML and Dart/Flutter with code examples. Finally, I'll quickly show a real industrial custom product developed and shipped with a Flutter UI application, the challenges and the result that we achieved.