If you're looking for a durable case for your iPhone 4 or 4S which would also keep the screen shielded even at the time of use, look nowhere else. The Griffin Survivor Case for iPhone 4 and 4S provides the best type of device protection without sacrificing usability. As one Amazon reviewer says:
Not completely waterproof, definitely water resistant. The iPhone sits inside a virtually fully enclosed plastic shell. Around that wraps a thick spongy silicone rubber case. The sleek iPhone ends up fairly chunky, but it is unlikely to get damaged and that's the point. The entire front including front camera is covered by a hard plastic sheet which doesn't impair touch function at all.
All ports, buttons and the camera are properly and firmly protected. If they're needed, however, one can easily push aside the spongy silicone protection and access the required area. The case doesn't affect audio quality either. Having spent some time with more than a dozen iPhone 4/4S cases, I believe this one is absolutely the best if you're looking for ultimate iDevice protection and a high degree of water resistance. It's been tested and certified to meet or exceed US Department of Defense Standard 810F and UK Department of Defense Standard 00-35. Griffin's Survivor Extreme-Duty Case is designed from the inside out to protect your iPhone from extreme conditions ... dirt, sand, rain, shock, vibration and a host of other environmental factors. It's also available on Amazon for less than $41.