Here is my entire lens kit with a mechanical pencil for size reference. It is an iPro Lens system kit for smart phones, made by Schneider Optics. These are about the most expensive lenses I have seen for phones, but the quality is worth it.
They include a 2x telephoto (making the iPhone a 84mm lens), a wide angle (equal to a 27mm on full frame) a super wide angle (equal to 19mm with MASSIVE distortion) and a micro that allows for 1" close focus distance.
Of course when I showed up to shoot the wedding on Saturday I had to use my big rig....
