Scratch it! is a free scratch / tapestop VST plug-in for windows, it is specially created for live scratching and tapestop effects.
A Z3 spokesperson told us, "With the envelope you can define how the stop button works on the audiosignal, it allows you to define up to 16 points in a synchronized beat grid, like this the stop button can act as a scratch sequence."
Pricing and Availability:
Intelligent Master Processing and Multiband FET Compression