Archimedean is great geometric tool I discovered recently via the Facebook page of GeoGebra. It is a tool for exploring polyhedral shapes. It is capable of transforming (e.g. truncating the solid’s corners or edges), and analyzing (e.g. showing the lines of symmetry or inscribed radius). Archimedean also allows the user to change the colors and other propoerties of the investigated solids.
Archimedean was created by Raffi J. Kasparian. It is very similar to Poly, another software for investigating solids.