A free app for Android, by SOFTDX.

It is very simple and easy to use, and it does not require root access to work. This is a free app that will turn your Samsung Galaxy S6 or S6 Edge into a torch. The only thing you need to do is to download it and install it on your device.

It works as follows:

When the screen is turned off, you can use the volume up key to turn on the torch.

On Galaxy S6/S6 Edge, you can toggle the torch icon, but using volume up key for it is certainly a very convenient option.

This is a very good solution if you are looking for a simple and convenient way to power on/off the LED flashlight on your Android phone to navigate through the dark.