decompile the apk. several tools available to decompile. You don't need to recompile or make any changes but it will show you the xml file you are looking for and you can easily open the text file and view all the string names you can change.
There may be other ways but this is tried and true. If you need a program to reference tho you can try apktool.
---------- Post added at 01:29 PM ---------- Previous post was at 01:27 PM ----------
Pretty sure it has to do with the app permissions to manipulate the sd card partition,.not sure if this can be worked around if for some reason WS decides to get back in the game.at least it is still usable from root of internal sdcard
And setting the priority doesn't work either....