@Override
    public void start() {
        // set some default settings in-case
        // settings dialog is not shown
        boolean loadSettings = false;
        if (settings == null) {
            setSettings(new AppSettings(true));
            loadSettings = true;
        }

        // show settings dialog
        if (showSettings) {
            if (!JmeSystem.showSettingsDialog(settings, loadSettings)) {
                return;
            }
        }
        //re-setting settings they can have been merged from the registry.
        setSettings(settings);
        super.start();
    }
<code>SimpleApplication</code> is the base class for all jME3 Applications.
<code>SimpleApplication</code> will display a statistics view
using the {@link com.jme3.app.StatsAppState} AppState. It will display
the current frames-per-second value on-screen in addition to the statistics.
Several keys have special functionality in <code>SimpleApplication</code>:<br>

 Esc - Close the application.<br>
 C - Display the camera position and rotation in the console.<br>
 M - Display memory usage in the console.<br>

A {@link com.jme3.app.FlyCamAppState} is by default attached as well and can
be removed by calling <code>stateManager.detach(stateManager.getState(FlyCamAppState.class));</code>
jme3-core/src/main/java/com/jme3/app/SimpleApplication.java