Examine source code of Growth Illustrated

{
  "manifest_version": 2,
  "name": "Growth Illustrated",
  "version": "1.0",
  "description": "Stay up to date with the latest news published by Growth Illustrated!",
  "permissions": [
    "tabs"
  ],
  "browser_action": {
    "default_icon": {
      "16": "logo.png",
      "32": "logo.png"
    }
  },
  "background": {
    "scripts": [
      "growthillustrated.js"
    ]
  },
  "icons": {
    "48": "logo.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{0d324faa-27f6-4b41-a5bb-1cf024fd2304}"
    }
  }
}