Android Studio is the official Android development tool available here
Open a layout file such as the activity_main.xml. Hide the project view and select “Split” mode to show the design and code at the same time.
Palette – contains available controls/widgets that we can drag onto the “design editor”
Component Tree – The component tree provides a visual overview of the hierarchy of the user interface design. Selecting an element from the component tree will cause the corresponding view in the layout to be selected. Similarly, selecting a view from the device screen layout will select that view in the component tree hierarchy