Are you a non-smoker or just out of lighter gas at a concert or festival? Does pulling out you phone and showing the picture on you lock-screen feel like a stupid thing to do to you? Than this is THE app you need!
Festival Lighter gives you an image of a lighter on you phone so you don't have to feel left out.
Disableling the automatic brightness adjustement of your phone might be a good idea but it will work fine if you dont.