title: App crashes when restoring from background after a long time
body: <p>My application crashes after idling for a long time in the background. I debugged and found the reason that it is crashing is due to a <code>NullPointerException</code>. Exception was due to the fact that the data in the application singleton class is destroyed by the garbage collector when application is in background. I am using static data in each activity throughout my application.</p>
  
  <p>My question is: is there any way to make the data of application class persistent when in background? Or is there any other solution?</p>