Feldspar is a virtual analog synthesizer featuring a range of tempo-based modulation options.

Main Features:

- 16 LFO waveforms.
- Ring modulator with 18 algorithms.
- Tempo-synced delay with high and low pass filters in the feedback path.
- Drift function for controlling oscillator pitch instability.
- FeldsparFX, a VST effect plug-in based on Feldspar's architecture.

More info
http://contralogic.com