It may be a little old but it is very powerful. Iris 2 from iZotope is an innovative, sample-based synthesizer that empowers you to create musical sounds like never before. Start by layering up to four distinctive audio samples, then use the spectrogram display and selection tools to spotlight the most interesting spectral characteristics.
And until the end of the month, you can grab it for about ten dollars!
iZotope Iris 2 is available with a 93% discount from Plugin Boutique until August 1st.