This RFID tag is really unique: it works with mobile phones just like other RFID tags, but you can reprogram it over I2C. The tag shows up as an ISO/IEC 15693 (13.56MHz) chip which is readable by phones and tablets. This could be interesting in situations where you want a tag that can be re-written dynamically when connected to a controller. For example, we did a test where we had a microcontroller write different URLs a few seconds apart, and the mobile phone detected the different URLs one after the other.