Skin disappeared after installing Xcode 6 iOS Simulator 8
Don’t use the simulator for device screenshots. Apple provides hi-res Photoshop files that have placeholders for your screenshots. Their status bars are also perfect, App Store-ready 9:41 AM works of art :)
Link: https://developer.apple.com/app-store/marketing/guidelines/#images
Update: you can also use frameit from Fastlane to automate this.