I have the same problem! Well the Windows Phone doesn't work with any readers you mentioned. Purchased phone only a couple months ago, and started a new job where having a "reader" is required! This is so messed up because my phone has no application whatsoever, zilch in working with "square". Which is my preferred choice! What to do? I am going to speak with Verizon because I may have to switch to a Apple phone. More fees, more of my time. Also, I'm somewhat angry with salesman because I explained my line of work, Independent Contractor, and you would think about what my needs were before selling me a phone that now I have no use for! This is crazy, your questions helped me, and the reply as well. However, I know that 3rd parties that developed the Software are not going to give me the answer I want. If there is a plan in future to have a App available, it will be too late. 