The achilles heel of the iPhone 4 is the camera lens cover. I don't like phone covers, so I never had one on my iPhone. I don't mind that the phone itself gets some slight scratches with use; that's just patina! But the camera lens cover got very scratched and cloudy, even though I only ever kept it in my pants pocket with nothing else to scratch it. I take tons of photos with my iPhone, but the camera was unusable.
I ordered a replacement lens cover, then realized I couldn't open up the phone to replace it. Thanks to the ifixt Liberation Kit, I was able to open the phone, replace the lens cover, and put it back together with the included phillips screws and driver in about 20 minutes. My camera is as good as new! Oh, and I now have my phone is a "bumper" type case that keeps the lens cover from dragging on things, so hopefully I won't need to replace the lens cover again. But if I do need to, it will be a simple matter thanks to the Liberation Kit.
Use a cover to prevent my issue. But if it's too late, get the Liberation Kit.