Unfortunately you are correct. I bought the Google Nexus primarily as a format for using the Square credit card reader and app to take credit cards at our sales.  I thought the form factor of the Nexus would be perfect. Then I discovered that not only is the square android app "officially" incompatible with Jellybean, but, worse, the card reader will not work with the Nexus jack since it is not a mic in jack. Solution? Bought a Samsung galaxy tab2 for the same $$. It runs android ICS and has a jack that works fine with square. Will now probably sell the Nexus and take a small (hopefully) loss. Really frustrating.