Volume Torchlight
volume-torchlight
About App
Samsung’s flagships let you use volume up key to turn on the torch when the screen is off, but Samsung has removed this feature from Galaxy S6/S6 Edge for some reason. If you find yourself using the flashlight as a torch more than most, you can bring back the feature on Galaxy S6/S6 Edge without root access.
You can use volume up key to turn on the torch in Galaxy S6/S6 Edge by installing a simple app called ‘Volume Torchlight’.
Developer info