TingedAce released a new version of XNand Healer GUI - an app that started off as an uncrippling tool but now morphed into a general purpose NAND dumping tool that should really aid the first part of the JTAG'ing process.
What's new/fixed:
* Big Block analysis and fixing now supported
* Now have the choice to fix NAND either from actual NAND or a virtual nand (image file)
* Added "CB" readout and exploitable indicator
* Added partial NAND analysis - can analyze images even if they don't start at block 0
* Added Absolute and Relative addressing in the Hex Viewer (to accompany partial NAND analysis)