Although it’s composed primarily of plastic, SuperCharge actually looks and feel quite nice. The curved, suction cup-equipped arm is connected by a ball joint to a rotating square on the back of the cradle. It’s held in place by a screw-on washer that can be loosened and tightened by hand, allowing you to get the arm just the right position. The square it’s attached to has three positions, allowing the iPhone to be used in a traditional…