Examine source code of New Tab Changer

{
  "name": "New Tab Changer",
  "version": "2.2",
  "manifest_version": 2,
  "description": "Load a custom web page or url in a new tab. Fast, light, and easy to use.",
  "background": {
    "scripts": [
      "scripts/background.js"
    ]
  },
  "chrome_url_overrides": {
    "newtab": "newtab.html"
  },
  "browser_action": {
    "browser_style": false,
    "default_area": "navbar",
    "default_icon": "images/16x16.png",
    "default_title": "New Tab Changer"
  },
  "options_ui": {
    "page": "options.html",
    "open_in_tab": true
  },
  "permissions": [
    "activeTab",
    "tabs",
    "storage"
  ],
  "icons": {
    "48": "images/48x48.png",
    "128": "images/128x128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{b622525a-f9f6-42a6-8b4b-230eed9afb25}"
    }
  }
}