I use my iPhone’s rear-facing LED flash as a flashlight all the time for various tasks, but I’ll be the first to admit that Apple could and should come up with a more intuitive way of toggling it on or off. In some cases, using a software button to toggle the flashlight just isn’t good enough, such as when you have wet or dirty hands.
Here to the rescue is a new free jailbreak tweak called SmartLight by iOS developer smokin1337, which spearheads a solution to these kinds of scenarios by letting users toggle the rear-facing flashlight on or off with the device’s hardware buttons instead.