I have too many projects on my other hand thats why i sell this website:
Find here most popular paid and free qr code reader app downloads. This list will be updated regularly and contains QR code reader apps available for iPhone and iPad devices, based on a search of the phrase: "QR code" at the app ranking-website TopAppCharts.com:
Personally i prefer the free barcode scanner Bakodo and Quick Scan. Both are completely free (24th. July 2012) and works fast and accurate. I have the feeling that the Quick Scan - QR Code Reader is a little bit faster than Quick Scan Pro. You should try it out by yourself. You find both reader on top of the ranking list. Take care, there is also a Quick Scan Pro version in the app store which costs some money. Not too much, only 99ct but the free version should be enough for most situations.