Examine source code of Galaxy Tour Builder

{
  "name": "__MSG_appName__",
  "version": "1.4.1resigned1",
  "manifest_version": 2,
  "description": "__MSG_appDescription__",
  "homepage_url": "https://github.com/TailorDev/galaxy-tourbuilder",
  "icons": {
    "16": "icons/icon-16.png",
    "128": "icons/icon-128.png"
  },
  "default_locale": "en",
  "background": {
    "scripts": [
      "scripts/background.js"
    ],
    "persistent": false
  },
  "permissions": [
    "activeTab",
    "storage"
  ],
  "content_scripts": [
    {
      "matches": [
        "http://*/*",
        "https://*/*"
      ],
      "js": [
        "scripts/contentscript.js"
      ],
      "css": [
        "styles/main.css"
      ],
      "run_at": "document_end"
    }
  ],
  "web_accessible_resources": [
    "images/gutter.png",
    "images/grip.png"
  ],
  "browser_action": {
    "default_icon": {
      "19": "icons/disabled/icon-19.png",
      "38": "icons/disabled/icon-38.png"
    },
    "default_title": "Galaxy Tour Builder"
  },
  "applications": {
    "gecko": {
      "id": "{b88158d8-6607-4404-8284-b904c58b5b02}"
    }
  }
}