This is my experience with flattring through QR codes on an iPhone: First of all it’s good that you made the QR code as large as you did because I still had to get quite close to the stage before the QR reader managed to interpret it (a higher resolution camera might do a better job though). I tried both iFlattr and QRReader and since both display web pages in their own internal web views I had to begin by logging into my account – which brought me back to the Flattr start page. iFlattr didn’t have a back button which made it pretty useless and I quickly deleted the app. The rest of my problems most likely had to do with a shaky mobile internet – pages not loading properly and my flattr click refusing to register at first. In the end the most robust solution seemed to be to open the Flattr thing in a proper web browser (e.g. Safari). I spent at least five minutes tapping around on the phone before I could finally get it to work.