At startup a graphical interface (GUI in the following) appears.
It is composed at bottom of the home, back, camera, parameters buttons along with a central list of buttons. Simply touch (click on a desktop) a button to navigate in the GUI. In general a button leads to a sub list or is a "leaf button" that permits to visualize something. The home button permits to return to the top list of buttons whilst the back button returns to the previous list. For example :
examples -> calorimeter
leads to the visualization of a simple electromagnetic calorimeter with a plotting area.
When visualizing something, the GUI disappears to let the place, full screen, to the "scene". A non visible "meta zone" exists at the bottom that permits, when touched (clicked on a desktop), to map again the GUI. (In fact the meta zone is visible once when visualizing the first scene). When having a scene, the camera button permits to map a panel that let you move around the camera (see the Camera panel section).