What a long title to a simple and really easy system.
But It took me some minutes to find how to manage to open my application activity when a nfc tag is read with a particular url.
Here is the trick :
<action android:name="android.nfc.action.NDEF_DISCOVERED" />
<category android:name="android.intent.category.DEFAULT" />
put this between
<activity></activity> to tell to the system that the activity can hold the http://*.google.com/* and should start it by default
It will also override the internet browser 😉