CTRXplorer
CTRXplorer is an open source SD file manager for the 3DS.
Download:
https://github.com/d0k3/CTRXplorer/releases Requires [devkitARM](http://sourceforge.net/projects/devkitpro/files/devkitARM/) and [citrus](https://github.com/Steveice10/citrus) to build. On Windows you will also need [info-zip](http://www.willus.com/archive/zip64/) in your PATH.