Just tried it on my razr, had no idea it was a thing but that's not surprising given I don't really set up accessibility features on my phones. You do have to be quite forceful with it, kind of whipping it back once at the end of a swing. Neat.

If you have tasker on Android or GOS there's a download for it called 'chop to flashlight' and can adjust the sensitivity so it doesn't turn on in your pocket or bag.