If you’re looking to add QR Code and Data Matrix scanning capabilities to the stock iOS Camera application, then a new jailbreak tweak called Decode Camera
by iOS developer ioshack may be worth looking into.
Just recently we showed you NativeQR
, but Decode Camera is just a little bit different in terms of feature list and usage. Notably, Decode Camera doesn't come with the Contacts QR Code sharing feature, but on the flip side, Decode Camera has a nicer interface