This is something I've been wanting to mess with for a while, and I finally decided to knock it out this weekend. You know, instead of going to support my friends bands and actually be social and things...
It's an analog-style (not actually modeled) octave down comparator fuzz. You can mix the octave down with the fuzz and the dry signal, and control the dynamics of the octave and fuzz separately, and the fuzz can be switched to do "octave up" via fullwave rectification.
The controls are named silly, but hopefully somewhat descriptive.
Written as a JS plugin for Reaper DAW. If you don't have Reaper, you should get it, but they also have a VST plugin called ReaJS that lets you load these plugs into other hosts.
Like any good fuzz, it sounds horrible on its own, but starts to get cool when you run it through an amp/cabinet sim. Being "analog" the tracking is instantaneous, and in my tests surprisingly glitch free. Of course, it wants single note inputs and just makes horrible noise on chords, but that's at least half the fun of the thing for me.