It's banal popup filebrowsing utility that should be available by default. Glad I found this at last, makes launching much easier. I depend on this parallel to gnome-do. Just the home item in the menue per default, so it will take up less space than the example picture suggests.
Very useful to navigate folders you use files out of often, without having to open a file manager. Offers configuration for more than one folder, so you can limit or broaden its scope as needed.