Syndt* is a high quality polyphonic synthesizer with a lot of possibilities.  The oscillator waveform can be morphed between pure sine to pure square, and supports altering of pulse width.  Both the shape and pulse width can be modulated by two independent LFOs.  With fine-tuned low pass and high pass filters combined with a separate filter attack setting, (optionally based on velocity) this synth can create some raw and interesting sounds. 

The additional LFO can be shaped exactly as the oscillator, and optionally controls filters, gain and pitch (using a modulation wheel or just automatically).  This LFO can be synchronized to a AUv3 host.