Until January 31, you can purchase Cableguys FilterShaper 3 for 30% off.
FilterShaper 3 takes a giant leap into unconventional sound design with two powerful filters, freely editable modulation curves, and a flexible modulation framework. The new Sallen-Key type filters deliver a rich, warm, intricate sound. Create complex, shifting, interweaving effects. Apply subtle nuances or giant wobbles. From filtersweeps and stereo tremolo to surgically-precise filter control and multiband sidechain effects.
More info, including a fully-functional demo version: www.cableguys.de/filter-shaper