[symstym]

Sounds cool. If you haven't already, you might want to check out the Fractal Bits iOS app. It doesn't let you manually adjust parameters, only randomly generate sounds, but it makes some nice ones. It sounds probably FM-based to me.

[dietrichepp]

I’m really going for a purposeful tool here that you can use to get what you want. Something a bit more than SFXR but a lot less than Reaktor.