At startup a simple graphical interface (GUI in the following) appears. It is composed for the moment of the home, back, camera 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 sub lists that finishes with "leaves buttons" that permit to visualize something. For example :
examples -> h/rand
leads to the plot of the normal distribution. The home button permits to return to the top list of buttons whilst the back button returns to the previous list.
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. When having a scene, the camera button permits to map a panel that let you move around the camera (see Moving the camera).