Custom scripts can be installed for all users (for easy distribution) by placing them in $XDG_CONFIG_DIRS/boop-gtk/scripts. If $XDG_CONFIG_DIRS is not set the default is /etc/xdg. Note however, unlike the users personal scripts folder, this folder is not watched and thus requires restarting the application to load new scripts.
If your looking for additional scripts see Boop's additional scripts.