Thanks to Josh for the idea to port two extensions to a one LPE. The extensions are Add Nodes and Jitter nodes. And the effect born as "roughen". I need some help to redefine the strings to make more easy to undertand. Also can work on widgets to visual make a separator from Add Nodes widgets and Jitter ones. Here are the code: https://code.launchpad.net/~jabiertxof/inkscape/roughen

Regards, Jabier.