I have modified the default polling mode of NfcService.java to poll for Nfc Tags even when the screen is off. This is done for the Nexus 4. To install move the old NfcNci.apk/odex from /system/app to keep just in case, and then just copy over the modified NfcNci.apk and change the permissions to 644. I used adb shell, and adb push to move and install the file in recovery mode, but any way should work. This is my first android development, so this may not work for everyone.



Update:

Just to clarify, this is made for stock 4.2.1



Update: 2/17/13

I have made a new version for stock 4.2.2. Just download copy to /system/app/NfcNci.apk and rename /system/app/NfcNci.odex file.