App for WebWorkers

I had the idea to build a simple app to provide WebWorkers for tasks of the user. Personally I would like to use it to find faces with HOG. This task would run in the browser of the user if its likes to find faces at some images.
This way there are no resources of the server used but the task is “outsourced” to the user. It might be helpful for installations on Raspberry Pis.

How could I make sure there is some little piece of JavaScript to make sure some WebWorker is waiting for task, globally? Is there an app like this already?

By the way: is there a app generator to provide some app skeletons beside the very basic one mentioned in the basic app tutorial?

Best regards