aaf709 that's a good point too.
Yeah try uninstalling the flashlight app, reboot, and try the camera again. I took a look at the app and it doesn't look malicious or that it would break the camera but you never know. Every phone is different. Good luck and hope you get it fixed.
Thanks for the help and advice, but I uninstalled the app, shutdown, and even removed the battery (just for kicks), and still can't open the camera. I guess a factory reset is next?