In Emily Fortuna’s article (and video) she mentions:
GlobalKeys have two uses: they allow widgets to change parents
anywhere in your app without losing state, or they can be used to
access information about another widget in a completely different part
of the widget tree. An example of the first scenario might if you
wanted to show the same widget on two different screens, but holding
all the same state, you’d want to use a GlobalKey.
Her article includes a gif demo of an app called “Using GlobalKey to ReuseWidget” but does not provide source code (probably because it’s too trivial). You can also see a quick video demo here, starting at 8:30 mark: https://youtu.be/kn0EOS-ZiIc?t=510
How do I implement her demo? Where do I define the GlobalKey variable and how/where do I use it? Basically for example, I want to display a counter that counts up every second, and have it on many different screens. Is that something GlobalKey can help me with?