As of Maya '15 and Unwrella 3.02, the procedure seems to have changed. The Unwrella menu is found under "Create UV's", has no tabs such as in the Tutorial vids, and most critically - doesn't appear to have an "Apply" button.
After hitting "Unwrap" I am given what appears to be a UV Snapshot (black background/white UV lines in Render View - not sure what else it could be) of the wrap it WOULD make, however it is never applied to the OBJ itself. The original map is still applied to the object, and the new map that is supposed to be created is not found anywhere.
All the tutorials using Unwrella appear to be severely outdated - using what appears to be Maya 8 (yikes!)
I would love to know where the heck the apply button ran off to.