nx_ftp, requires a file system, which WICED doesn't support. We have recently been working on implementing TFTP protocol, which is (as the name implies) doing file transfers as well (a trivial one though). it is still a preliminary version, but I can attach it here, if any one is interested.
Please find the attached zip file for adding TFTP support, please note this is a preliminary version, it hasn't gone through our SVT (System verification tests) yet. I'd appreciate feedbacks. Also please give a good attention to firewall limitations posed by windows.
Have a look at the snip application for the API and usage.