GIS manager
Q: Is it possible to add a menu item to the GIS manager window in a similar fashion. Any tips and hints on how to add on an extra menu item in the gis.m gis manager?
A: Edit
$GISBASE/etc/gm/gmmenu.tcl
Or alternatively, create $GISBASE/etc/xtnmenu.dat file, or <dir>/xtnmenu.dat for any <dir> in $GRASS_ADDON_ETC. Examine the code at the top of gmmenu.tcl for the format of xtnmenu.dat (TODO: add more precise info here)