Noisebud has released Noisebud Filter 2.5 for Windows, a free audio filter effect.
Here's what they have to say about it:
Noisebud filter consists of a lo pass, hi pass, band pass and a band reject filter wired in a parallel chain. Every filter can be controlled by a three LFO’s where one is extremely slow (a sLoFO). Every filter has a invert button so that you can silence frequencies that collide during heavy LFO movements, this is probably what make Noisebud filter in somewhat special. We recently added the possibility to keep a bit of the dry sound and added a limiter in the end of the chain since this puppy is a bit on the wild side (well, it’s a Noisebud after all).