Bluetooth RFID Tagreader
Update 2013-07-20: I published all files necessary to create such an RFID Tag Reader on github: https://github.com/michaelkroll/BT-RFID-Reader
Some time ago I started a small project to create an RFID Tagreader which is connectable to iOS devices. In order to setup a bidirectional connection to a Bluetooth Accessory you must be participate in Apple’s MFi Program http://developer.apple.com/programs/mfi/. In the case where only the UID of an RFID Tag should be transferred to an iOS device, an accessory could act as a Bluetooth Keyboard (which is the only Bluetooth Device which will be discovered by iOS as well as Bluetooth Headsets).