I had to order a cable for it to work in my Iphone 4S with the Otterbox because it would not seat all the way down. The cables at Radio Shack will not work. I found these on the internet at Cell Pay. Also, if you are in a metal building, you will have trouble connecting, unless a Wi-Fi is available nearby. Good luck with the show and the Square. I also use the Intuit Go Pay system.
Tony,aka,Toneman