The built-in Google Search widget can decode QR codes! Android Phones have a built in QR Code Reader. Google Goggles reads QR Codes and is also integrated with the Google App for iOS devices.
To scan a QR code, you need to tap the microphone icon inside the Google Widget and then choose “Search with Camera” option from the menu available in the lower right corner.
Now point your mobile camera to any QR Code, tap the on-screen camera icon and it will instantly reveal what’s stored in that QR Code. You’ll also find Google search results for the decoded QR Code.
I have tried this on Nexus, Samsung and Motorola phones running Android 4.2.2 (JellyBean).
Tested on the iPhone5 too!, Select Google Voice search, tap the camera icon and take a photo of the QR Code!