Luxury leather goods maker AB Sutton has introduced its iPhone Simple Slip case. The iPhone Simple Slip is made from kidskin leather with dupioni silk interior lining. The case comes in two styles — with and without a wrist strap — and customers may also add a silk monogram to the outside of the case. The iPhone Simple Slip case is available now in a large variety of colors and with a multitude of different silk linings. It sells for $48…