get-manifest-external
Include this file in a Chrome App or Extension's background page and it will allow you to request the manifest file from an external page.
Usage
Installation
npm install get-manifest-external --save
background.js
// require the file in background.js; // or import the file into background.js (requires babel);
manifest.json
... "externally-connectable":
External page
chromeruntime;
Why?
Can be used to check if an extension is installed as well as displaying the currently installed extension's version.