RFID cards as tokens (Mifare Ultralight)


I use the Nexus 7 in my setup, but when I try to assign tokens to users so that they can identify themselves with their RFID-cards the Kegbot app doesn’t read the tokens. A program like NFC reader from Google Play has no problem reading my tokens through the Nexus built in NFC reader. Is there some app I could download to make other apps like the Kegbot app recognize my RFID cards? When I try to assign tokens to users in the tokens setting window in the server software (1.1.1) the Nexus do read the token (beeping sound) but no identification number appears…

I use RFID cards with Mifare Ultralight chips.