If You write less than 16 bytes the extension add 0 tho the remain bytes The data to be written must not be greater than 16 bytes, HEX format. The Mifare Tag must be near the Android device. Write the Block specified (after the authentication) with a number between 1 and the number of blocks minus 1. The extension calculate the Sector to authenticate Read the Block specified (after the authentication) with a number between 0 and the number of blocks minus 1 The Mifare Tag must be near the Android device Provide the Key A necessary for the Mifare Classic Authentication after this it is possible Read or Write a block if the Key is correct and has the permission to do it. True to read a block, false to write a block Provide all the info data of the last Mifare Tag approached The following events work when You approach a Mifare Tag to your smartphone with the app opened: The extension have some events and property and functions here a small explanation. In this version I have added some feautures: This is the new version of my MifareInfo extension.