i think it's a good idea, but i'm not saying i'd buy one.
the iphone 4S and iphone 5's camera is the best on the market.
i have the cheap detachable macro and wide angle lenses and they work perfect.
it's cool that someone has developed a case that is just much easier to use.
but still, as a photographer, i wouldn't buy it or use it. i have my D700 for pictures.