Examine source code of Instant Feed

{
  "manifest_version": 2,
  "name": "Instant Feed",
  "version": "1.1resigned1",
  "author": "addonDeveloper",
  "description": "Enjoy subscribing your favorite websites",
  "icons": {
    "48": "/img/icon48.png",
    "96": "/img/icon96.png"
  },
  "permissions": [
    "storage",
    "<all_urls>"
  ],
  "browser_action": {
    "default_title": "Instant Feed",
    "default_icon": {
      "16": "/img/icon16.png",
      "20": "/img/icon20.png",
      "32": "/img/icon32.png",
      "64": "/img/icon64.png"
    }
  },
  "background": {
    "scripts": [
      "bg.js"
    ],
    "persistent": true
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{76ee6010-a6b7-4b81-b0ed-94b5b2945eea}"
    }
  }
}