I initially downloaded this for the "telephone" effect, which you hear a lot in modern pop recordings. (sounds like your voice is coming through a telephone mic and out of a telephone speaker) it works great for that on the preset called "cold turkey" or something. but I found myself using it a lot more than I expected for general shaping of sounds. you can get some great lo fi sounds, and you can even make your acoustic guitar sound like an electric more or less. the presets are a good place to start, there's a decent variety of sounds in them. I wasn't sure how to rate some of the categories so I just guessed and gave 8s. it's pretty easy to use, you draw the curve, and adjust the filters. in my brief experimentation I found that the most sensitive area of the curve is on the left side. sometimes adjusting farther to the right doesn't seem to do much of anything. it's a very digital sounding clipping, at least for what I've gotten out of it, but it's a lot of fun. in one instance I put it on an electric guitar track, an intro, and it brought out sort of a Vox amp flavor underneath all the fuzziness, which was cool, that boingy sound. and used it to lightly rough up the rest of the guitar track, which was a bit flat and sterile sounding.
also great for grunging up midi drums, which sound really boring and weak to me without the effect.