LV 2015 (re-)introduces the ability to write plug-ins in G that affect the edit time panel and diagram shortcut (aka popup) menus and the run time diagram shortcut menus. Some plug-ins ship with LabVIEW, but dozens more (as of this post) are available here:
http://ni.com/lvmenus
If you wish to write and share your own plug-ins, you can upload them to the community, though it won't surprise me if LAVA develops its own repository for such things.