This is a simple but effective standalone Python scripts that allows you to sort 3DS ROMS on Gateway/MT Micro SD Cards.
Python 3.4 or above
Download and run py3DSorter.exe for Windows users. For non-Windows users however, extract the scripts attached to this thread and run it from Python IDLE 3.4, tkinter could not be ran normally.
Editing the scripts is allowed but don't forget to credit.
Big thanks to Mthodmn101 on Maxconsole for compiling it for Windows.
Download for Windows here: https://www.mediafire.com/?0mtwjw684n33154
As seen on MaxConsole.