Noisebud Filter is freeware filter effect plug-in for Windows.
Noisebud Filter consists of 4 filters (or 16, depending on how you look upon it), they are switchable between Lo pass, hi pass, band pass and band reject filter.
The signals from the four filters are wired in a parallel chain. Every filter can be controlled by three different LFOs where one is tempo-synced; one normal and one extremely slow (a sLoFO).
The LFO sections also have something Noisebud call VariFO. It adds another movement to the LFO and makes it less predictable.
Every filter has an invert button so that you can silence frequencies that collide during heavy LFO movements, this and the VariFO is probably what make Noisebud filter special.