Yes, yes, I know (under Windows Phone 8.1) you can get to QR scanning through the 'Bing Vision' camera lens, but that's a bit of a round about way to come at the task. Better to have a dedicated application and even better if it's terrifically function-rich and also updated often. Enter QR Scanner+, which has just gotten faster and a lot more capable.

From the official QR Scanner+ changelog:

• Added recognition for 'mailto:' (URL encoding)
• Added license info @ about
• Optimized recognition-algorithm
• Fixes @ light theme
• Added Rapid Scan / see settings
• Added interaction with QR Generator
• Added continuous AutoFocus / see settings
• Added customizable tile / see settings
• Added SEPA (Giro Code) recognition
• BugFixes

Quite a big update then, since I last looked at the application in detail here,

The addition of auto-focus in settings (right) gives extra flexibility, previously is was 'tap to focus' only (left). The Settings panes and dialogs are very comprehensive.

A terrific tool that's earned its place on the Start screen of my WP 8.1 Update 1 (i.e. Cortana-ed!) Lumias. Grab it here in the Windows Phone Store.

PS. I still don't see why Cortana can't recognise 'Scan a QR code'.... maybe this will happen in the future!