I was in the Apple store in Kingston UK earlier today having a play with the demo 5s units. I noticed something weird on the first one so I went and checked really carefully on 3 other units. None of the units had the "Contacts" app icon anywhere on the home screens. I went through every screen and into every folder and it just wasn't there. it's accessible from the Phone app but the icon to launch it directly didn't exist. I was worried it might not be there on iOS 7 for iPhone 5s so I asked a sales rep. He hadn't noticed the issue so he came over and had a look and couldn't find the Contacts app on any of the demo units either. He got out his personal 5s and it was on his home screen so it's obviously something weird with the demo build that was being run. Have other people seen this? The other thing that I noticed was a very big difference in screen brightness between different units. I ended up holding two side by side and checking that both were on maximum brightness with auto-brightness off, they both were but one was way brighter than the other.