With this method, you don't need to put on your phone to activate your flashlight, all you need to do is draw a secret sign on your screen and your flashlight would come on.

Here is how to activate it.
Step 1 : Go to settings.

Step 2 : select the smart assistant

Step 3 : click on micro intelligence

Step 4 : select quick start

Step 5 : look for your preferred secret sign from the option and select it.

Step 6 : Select toggle and click on flashlight.

That's all, so anytime you draw the sign on the screen, the flashlight turns on.