How do I access the in-app developer menu?

In React Native, the developer menu can be accessed by shaking your device: ⌘D
for the iOS Simulator or ⌘M for Android emulator.

In Flutter, if you are using an IDE, you can use the IDE tools. If you start
your application using flutter run you can also access the menu by typing h
in the terminal window, or type the following shortcuts:

Widget hierarchy of the app

debugDumpApp()

Rendering tree of the app

debugDumpRenderTree()

Layers

debugDumpLayerTree()

Accessibility

S (traversal order) orU (inverse hit test order)

debugDumpSemantics()

To toggle the widget inspector

WidgetsApp. showWidgetInspectorOverride

To toggle the display of construction lines