i dont think so. i've been using a flashlight app since 3 years now... no issues reported. ofcourse, i dont use it for hours together, but every now n then when needed.
I don't think enough people have used their flashlights for that long to figure this out.. You'll probably have to keep it on for quite some time for it to "burn out"...
I have that app, but i rarely use it. it's mainly for emergencies..
Been using a flashlight app since the iPhone came with a flash. I use it almost daily and never had a single problem. In super shocked ur just discovering this now. I'd bet 95% of all smartphones (not just iPhone) on the planet have some flashlight app installed.
I assume Apple considered the LED being on for extended periods (heat dissapation being the primary concern IMHO). LEDs themselves are generally considered to have a lifespan 50,000 hours so "burning it out" is not a concern. I use mine as a flashlight whenever I need to for as long as I need to.