I don´t see why you would use one if those when almost everyone has a phone in their pocket these days. Usually with and app or NFC chip that will do those things.
Indeed, smartphones can do a lot of things, but not one thing particularly well. My original goal with this design was to replace the 'card wallet' apps for phones, as the barcodes never seemed to scan very well through the glass screens. I've narrowed it down since then to be more for toying around with Arduino/e-paper development, at least for this iteration.
