Excellent case study indeed, I enjoyed the insight into your design thinking! Was the potential employer cool with you posting this article? I realize that the work you produced was in fact your own, but I’d be interested to know why the client didn’t have you sign a nondisclosure or something to protect themselves from giving away anything “hush, hush”. Also, to protect your intellectual property, you should have had them sign one as well to keep them from using your work because you have some great ideas for their app in there.