EZSkin is updated and is maintained on this site:

https://cobrablade.net/snarlygribbly/poser.html --you want EXSkin 3.2 for Poser 13; this is for skin conversion (and some hair)

The other is GoPhysical:

https://www.renderosity.com/marketplace/products/157575/go-physical-for-poser-12

(works for P13 as well as P12--this is for other materials)

There are others, but those two can make old content really good looking again.