With Tagipedia on iOS, you can scan QR codes and discover the information behind them.
Tagipedia approaches QR codes in a unique way in that it acknowledges the fact that information about a single barcode could be retrieved from multiple sources (services). Upon scanning a barcode Tagipedia will list the different services that can deliver information about this barcode. You can then choose any of the services to gain access to information about the item being tagged.