i also having problem of Camera Not Working on my iPhone, but i tried given steps and easily get rid of on issue.
1- Reboot or Restart iPhone
2- Close camera app from app switcher
3- Dark area Enable Flashlight
4- Check for enough storage space,
for more info with screen read this thread
Is that camera app not working properly on your iOS device? I have the same issue on my iPad. According to my experience, you can force quit this camera app firstly. If it fails to work, try to check if a system update is available. If there is one, just download and install it . Of course, you are able to force restart or factory reset your device. If you are afraid of losing data with these methods, you can put a repair tool to use. I have used Joyoshare UltFix to fix my iPad camera issue. It won’t cause any data loss. Whichever method you use, wish it can work you out.