If you know Java, the Dart language should feel very familiar.

All of the app’s UI is created in Dart code.
For more information, see Introduction to declarative UI.

The app’s UI adheres to Material Design,
a visual design language that runs on any device or platform.
You can customize the Material Design widgets,
but if you prefer something else,
Flutter also offers the Cupertino widget library,
which implements the current iOS design language.
Or you can create your own custom widget library.

In Flutter, almost everything is a Widget.
Even the app itself is a widget.
The app’s UI can be described as a widget tree.

Step 1: Show the Welcome screen