title: Uninstallation password
body: <p>I am making one phone security application in android.
  The point where I stuck is that How to set uninstall password for this app.
  When application is installed user can set the security password and this password will be used for uninstalling this app.
  So please someone suggest me how to put code for uninstall event.?
  Is there any event or service called when apps are going to uninstall.?</p>