Chris Wolfe has released Jasuto, a modular synth for iPhone and VST.
Jasuto is very flexible in terms of synthesis techniques. You can achieve additive, subtractive, FM/PM/AM and even hard-sync synthesis all pretty easily.
Both the synth and all the parameters are in one object called a scene.
A scene is made up of nodes, these are the objects that do the processing and what you directly manipulate to make, modify or otherwise bend the sound.
Jasuto will initially be available from the iTunes App Store for $1 USD. The Mac and Windows VST versions have no iPhone or Midi support yet, and you should expect plenty of bugs, but it is available as a free download here.
Jasuto is still under pretty heavy development, so it will be improving/changing quite often. Feedback will certainly have an influence over the development direction.
Visit the Jasuto website for more information.
Link via CDM