Video: Selling Doughnuts with Square and iPad Xavier Lanier09/29/2010 I just got my Square dongle in the mail, but haven’t had a chance to set it up to start accepting payments. Square is a little dongle that turns any iOS device into a credit card swiper and cash register. One thing holding me back from actually using it is that Square gave me a pretty low monthly limit. I was at the San Francsico Ferry building for lunch on Sunday when I spotted a guy selling doughnuts with an iPad. I saw that he had a Square plugged in and he gave me a quick demo of his setup. Advertisement The doughnut vendor was selling organic, vegan doughnuts for $3 a pop. I liked how he was using Square, but I passed on the organic carmel mushroom vegan doughnut. For some reason it didn’t sound as appetizing than an old fashioned unhealthy doughnut.