Resume the Top Activity instead of starting the Launcher Activity

Try using the following code in the onCreate method of the activity that is specified as the Launcher Activity in the Manifest, i.e. the ContentDownload activity from the original code posted in the question:

if ((getIntent().getFlags() & Intent.FLAG_ACTIVITY_BROUGHT_TO_FRONT) != 0) {
  finish();
  return;
}

This will finish your Launcher Activity before it is displayed by detecting that there is already a task running, and your app should instead resume to the last visible Activity.

See this page in the Android documentation regarding Android Manifest launchModes: http://developer.android.com/reference/android/R.styleable.html#AndroidManifestActivity_launchMode