This is indeed a great idea, and I would (will) register a copy if it's ever updated to allow icon-less widget apps to be created.

I really like the idea of being able to run widgets singly, and at present I'm using Amnesty (original version, not Singles) to put a handful of useful widgets on my desktop. I like what Amnesty Singles does, but the apps it creates install an icon in the Dock when they're running, which I'd like (optionally) not to happen.

If the software could be updated to allow the option of creating apps that have neither Dock icons nor menu bar items, then this idea would work even better.