The upper right part of the display shows dynamic graphs of the
instantaneous velocity, horizontal position and acceleration of the
pendulum bob. After the end is reached, the graph restarts but now shows
total energy, kinetic energy and potential energy. The next time the
original type of graph is again shown, and so on.

Use F7 to stop the action at different points of the motion and notice at
what points the potential and kinetic energies are smallest and when they
are largest. Notice that these two energies always add up to the total
energy. If you turn on some friction with F6 you can see how the amplitude
of the motion and the total energy decay with time. The program restores
the initial amplitude each time the graph recycles. While the friction is
on, compare the two types of graphs. Notice how the total energy decays
faster than the oscillation amplitude. Think about this and try to find the
explanation. Use  F6  to turn friction  ON  and  OFF.

The lower right part of the screen shows the pendulum formula for small
amplitudes and the basic quantities which define the motion of the pendulum
pictured at the left side. When you stop the motion, other numbers are
listed, which show the instantaneous values of several dynamic quantities.
Many of these values are related through the pendulum formula, through the
law of energy conservation, etc. Try to find and verify such relationships. 