http://www.synthmaker.co.uk/index.html
Headline says everything. Back in this thread everyone either just rushed to download the VST thing and missed this awesome program or nopony is interested.
This is ridiculosly easy to use. Just take a look at the example synth and you should be able to figure it out. Any VSTs created in the free version generate a noise burst though and the full version is quite expensive.
(VSTs work just fine when they are used within synthmaker, so you can try to record in to something else, or maybe upload the ready schematic on the forum and ask someone with the full version to do the plugin for you. That's if your wallet isn't fat enough. [Like mine isn't.])