title: What method to override to know when the application exits from any screen
body: <p>I have to do a clean up of some app generated files, when the application is completely closed. The close can happen from any screen. Which method or where should i override globally to caputure Menu Close event, rather than overriding onClose() on each screen of the application ?</p>
  
  <p>And when the application is closed using Menu Close in the middle of the application, is onClose() called for each screen on the stack and are popped off the stack, or it just removes the application from memory ?</p>