public MySimpleTracker()
{
  AppDomain.CurrentDomain.ProcessExit += new EventHandler(OnProcessExit);
  TrackerEngine engine = TrackerEngine.Instance;
....


public void OnProcessExit(object sender, EventArgs e)
{
  Console.Write("shutting down the Tracker...");
  //TrackerEngine.Instance.Stop();
  Console.WriteLine("done");
}