Leathl has released ShowMiiWads 1.2:

ShowMiiWads is a 'Wad File Manager' for Windows. It displays information about wad files, edits them, gives a preview of the Banner and Icon and more. New since Version 1.0 is the included NAND Backup Browser 'ShowMiiNand' which displays all titles installed in your NAND Backup (No BootMii Backups!).

Due to some people stating this as a piracy tool, I just wanted to clarify that I'm all against piracy and this tool was never intended to be used for!

Changelog
Version 1.2
Fixed a bug that caused ShowMiiNand not to load the List with the saved entries
You can replace Banner and Icon images (the resultant U8's can be Lz77 compressed!)
Added Dol Insertion (uses Waninkokos Nandloader)
Installation to Nand does now update uid.sys, if required
Improved Virtual Console detection to display System (NES, SNES, ...)
Fixed U8 Unpacking (Now works with every proper U8 archive)
Added batch renaming including variables, e.g. {titleid} (use 'Rename' button)
Added ability to Backup and Restore save data
Added some Tools (U8 Packing, Lz77 Compression, ...)
Deleted 'Pack Wad Without Trailer', just delete the trailer file if you don't want it :P
Bugfixes and Improvements
Added editing of IOS Slot (Note: Both these features are untested and dangerous!)
Added editing of Title Version (Use them at your own risk and only with BootMii/boot2!)

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