OttoPhilter is the 7th of the Twister Series, a new line of Audio Unit effects from Music Unfolding.
OttoPhilter is an auto/touch wah filter with LFO control and sub-octave generation and a second auto/touch wah filter on the sub-octave.
There's a level meter tied to the touch wah sensitivity to help you adjust OttoPhilter to suit your playing dynamics. OttoPhilter has two driven resonant filter sections - one on your input signal and one for the generated sub-octave. The filters sweep by using triggered envelopes or tracking the input signal or using LFOs.
OttoPhilter is $19.99 and is available for OS X as a Universal Binary. Download a demo of OttoPhilter here.