The SketchUP Import doesn't appear to be available or it's already bundled with the SketchUP application. I've checked various websites, but there isn't anything related to this application which I believe it was used to import various content into the SketchUP software.
However, you can see on the following link what are the file types supported by SketchUP: https://help.sketchup.com/en/article/3000153
