Why won't the flashlight work on my iPhone?

I downloaded the flashlight app and the light won't turn on

I'm guessing for the iPhone 4 maybe you broke the lense for it

I am wondering the iphone you have is iphone 4/4S or iphone 3GS?
3GS has not the flashlight. Btw, if it won't work on your iphone 4/4S, mayba there are some porblem with your iphone. Go to the apple store to rapair it.

_I would like to TravleChina.HK

Why won't my back camera or flashlight work on my IPhone 5c?