Ask HN: Anyone want to help me build a third-party script manager app?

Is there an app to manage all the third-party JavaScripts on a website? What I want is something that I can add scripts or snippets to, arrange them in order, and decide whether to load them synchronously or asynchronously. The the app will minify and concatenate, creating a loader script and uploading it to CloudFront.

I could use this app, this is a simple example, to setup a script to load jQuery synchronously THEN load Visual Website Optimizer synchronously, wait for the document to be ready, THEN load Google Analytics asynchronously. I can do this manually, but if this could all be managed from a web UI, it would be great.

A lot of my clients have so many scripts that they don't even know what is on their website. I want to give them a single script and then manage the loading of third-party scripts from an app.

I've thought a lot about this and I have the process diagrammed out pretty well. But I'm a front-end guy who's dabbling in Rails and I'm not at the level yet to build out what I'm planning. Is there anyone who'd be interested in creating a MVP based on this idea? I can provide wireframes, diagrams, UI, and directions. It's kind of a niche idea, but I think there are some extra features that can turn it into a SaaS people will pay for.