Something like this has existed for Polymer.js for a while now called Polymer Designer - https://polymer-designer.appspot.com/ https://polymer-designer.appspot.

Something like this has existed for Polymer.js for a while now called Polymer Designer - https://polymer-designer.appspot.com/ https://polymer-designer.appspot.com/ I think as web components start to become standardized we'll see more and more of these types of tools that make it easy to click interface elements together using a GUI.