If I understand correctly it depends on how well or badly behaving the applications are. I believe the judgment Android makes to close down an application is pr

If I understand correctly it depends on how well or badly behaving the applications are. I believe the judgment Android makes to close down an application is primarily free memory (not battery life). This gives a basic overview of how application activities behave (see the diagram a few lines down): http://developer.android.com/guide/topics/fundamentals.html#actlife http://developer.android.com/guide/topics/fundamentals.html#... It is possible for a badly behaving application to create a thread which would continue to run whilst an activity is not visible. Take this as a common example for an Android game app framework: http://www.helloandroid.com/tutorials/how-use-canvas-your-android-apps-part-1 http://www.helloandroid.com/tutorials/how-use-canvas-your-an... Your app may need (implementation specific) to take explicit action (SurfaceView::surfaceDestroyed) to stop the rendering thread before being backgrounded,