If you have a .rb file named bz_toolbar.rb , open it in a text editor to check the author/description.
Access it via the SketchUcation Plugin Store . You will also need the LibFredo6 shared library, which is a required background file for all Fredo6 plugins. How to Install: sketchup bz toolbar
It draws curves in 3D space, which is essential for modeling complex forms like modern furniture or organic roofs. If you have a