Android Market QR Codes WP Plugin by techcredo lets you easily create clickable and customizable QR codes for any Android app in the Market.
The Android Market QR Codes WP Plugin uses WordPress shortcodes feature.
Surround any link to an Android app in the Web Market or on AppBrain.com with “qr” “/qr” in brackets, and this plugin will create a clickable QR code for that app. You can also just supply the name of the app, but the first two methods are recommended. The appearance of the QR codes can be customized from WP Admin > Settings > Android Market QR Codes.
Plugin homepage: http://www.techcredo.com/random-tech/android-market-qr-codes-wordpress-plugin