In the past few years it has become commonplace to say that the QR code is dying. Few activities in mobile computing make use of the code, and in other cases shortened, easy-to-remember URLs have become more practical and elegant. However, with the popularization of blockchain technologies this can change, and QR codes may finally find a useful case for mainstream adoption.
Right, so how about a useful link: http://www.bitcoinqrcode.org/ ...and there are others...