Abstract: The invention relates to an application development tool that employs a tree design environment as the graphical user interface on a computing system's display. The development tool allows a developer to create an application graphically and within a window of the display by defining a plurality of nodes that together form a tree. Each of the nodes represents a screen to be displayed to a user when the application is executed or an activity to be performed when the application is executed. In response to selecting a node, the development tool automatically moves one or more nodes, collapses one or more branches of the tree, and expands one or more branches of the tree within the window to show the selected node and also one or more nodes before and after the selected node within the available space of the window and without changing the size of the window.