Wrap your WidgetsApp with Storyboard.widgets().
Wrap your CupertinoApp with Storyboard.cupertino().
Custom Routes and Widgets
You can add any number of custom widgets to the canvas, including custom routes. You can add dummy data to the constructors here as it will render all default values.
Now you can test all your screens with a hot reload! You can also disable the widget at any time by setting enabled to false. You will need to do a hot restart after you change this value.