Nokia has updated its NFC Writer app for Lumia Windows Phones. Version 18.104.22.1680 sounds as though it was a minor bump and you'd be right to assume such a thing. The only notable difference we can spot is the addition of a "NFC Tags" entry on the main menu. This loads a screen that explains why users should purchase and use official NFC tags from Nokia.
As well as some information, there's a link to purchase the NFC tag pack (containing 5 writeable NFC tags) that will take the user to Amazon - though when we try the link outside the US it appears to crash the app). You can download NFC Writer from the Nokia Collection on the Windows Phone Store.