While some Fredo6 plugins have moved to a paid model, many essential utilities like FredoScale and Curviloft remain industry standards for organic modeling.
Building your own "plugin pack" ensures that every tool is compatible with SketchUp 2021’s Ruby API and free from viruses. Start with and Extension Warehouse to gather the specific tools you need for your design niche.
Allows you to push/pull curved surfaces—a feature SketchUp’s native tool cannot do. The Best Official Sources for Free Downloads