Which phone do you have? Does it have a front facing camera? When you search for apps in your all apps menu are you selecting to show system apps too? I've had a fair number of HTC phones and I can't remember if you have to do that to see it there. Does it show up in your app drawer and are you able to open it at all? Have you tried downloading another camera app to see if it works? Have you tried your flashlight to see if the led works at all? I'm trying to remember but I think the camera and the led are one unit in the phones I've opened up so if the cable came unplugged that might account for your camera and led not working but I can't figure out the lack of a camera app...? If the phone has taken a sharp blow that could have caused that cable to come off, they're just little snap together ends. Are you willing to open the phone to check the connections or were you planning to turn it in on insurance?