title: Android: Make app transparent and act on the background application
body: <p>Is it feasible to make our Android application completely transparent (as if its not active at all) and work on the other apps? </p>
  
  <p>My Requirement:</p>
  
  <p>First last an app and after some few settings, make it transparent. Once its transparent, the user will not know that this app is active, however, our app should respond to only specific controls. </p>
  
  <p>This is because of the Broadcast receiver limitation, I will have to use the Volume button for some actions in my application. But, this button doesn't broadcast. So, currently I am using Power button which is not the requirement. </p>
  
  <p>Please throw some light on this. I did some research but, couldnt find any. :(</p>