Please note that it requires another plugin from Smustard called Progress Bar. It has not been submitted to the Extension Warehouse but can be downloaded from.
There are several STL plugins, but I suspect that one written by the SketchUp developers would be the best for integrating with SketchUp. SketchUp STL – this plugin is needed to import and export STL files.Here are some recommended extensions as an update to those previously assembled here. There is an Extension Warehouse that can be called by clicking on the button (below) located on the toolbar.
SKETCHUP FREE DOWNLOAD 2014 INSTALL
Trimble SketchUp now hosts a repository for SketchUp plugins that one can access and install directly from SketchUp Make or Pro. As mentioned previously, SketchUp 2014 has a new scheme for installing plugins.