Teehan+Lax Company is over there for last 10 years and they are creating PSD for IOS over the past 5 years. Previously they have created very beautiful and crafty PSD for Iphone, ipad and Android GUI.
Recently they have released very beautiful PSD of IOS that is used in iphone 5. The PSD is high a resolution (3000×3000) well labelled layered file that contains almost all GUI elements that are available in IOS6 for iPhone5.
The current version and the previous versions of IOS PSD’s are available to download for free of cost.