If you are using a Flashair SD to save having to remove it from your printer then this makes it a lot easier to use.

http://www.extrud3d.com/fashairui

You do need to copy the "List.htm" AND the directory "js", the instructions do not make that clear.

If you are not using one of these then you should be. SD card slots and SD cards are pretty fragile and this just means you never need to take it out of the printer.

File refresh is a bit hit and miss but I find that on my Wanhao (Sailfish) I can force a refresh by descending two directories and back after I copy the files on. Another option is to always use the same file names and overwrite rather than write a new file.