MifareClassicTool (MCT) is a Android NFC app for reading, writing, analyzing, etc. MIFARE Classic RFID tags. It provides several features to interact with (and only with) MIFARE Classic RFID tags. It is designed for users who have at least basic familiarity with the MIFARE Classic technology. You also need an understanding of the hexadecimal number system, because all data input and output is in hexadecimal. A list of features can be taken from the readme. This app was initially developed as part of my internship semester at SySS GmbH.
Update 16.05.2013: The app is now available for download on Google Play.
Update 08.10.2013: The app has be greatly improved as part of a semester project. You can find more information about the development here.