I've tried a couple of fl apps, but they all require an extra tap after you hit the icon to turn on the light. Is there a flashlight out there that illuminates immediately when you upem the app?
I just installed Tiny Flashlight + LED on my phone. In the settings there is an option to change the default state from "off" to "on". Default is "off" but when I changed it to "on" the light comes on as soon I start the app. You can get to the settings from the circle in the top right of the screen.