Examine source code of Fullscreen Maps

{
  "manifest_version": 2,
  "name": "Fullscreen Maps",
  "version": "1.3.6.1resigned1",
  "description": "Online maps without the clutter. Hide the UI for your favorite maps website and enjoy a fullscreen map experience.",
  "icons": {
    "16": "icons/icon_16.png",
    "32": "icons/icon_32.png",
    "48": "icons/icon_48.png",
    "128": "icons/icon_128.png"
  },
  "background": {
    "persistent": false,
    "scripts": [
      "background.js"
    ]
  },
  "page_action": {
    "default_title": "Toggle User Interface",
    "default_icon": {
      "19": "icons/icon_gry_19.png",
      "38": "icons/icon_gry_38.png"
    }
  },
  "permissions": [
    "tabs",
    "activeTab",
    "storage"
  ],
  "content_scripts": [
    {
      "matches": [
        "*://www.google.com/maps*",
        "*://www.google.com.ar/maps*",
        "*://www.google.com.au/maps*",
        "*://www.google.at/maps*",
        "*://www.google.bs/maps*",
        "*://www.google.be/maps*",
        "*://www.google.com.br/maps*",
        "*://www.google.ca/maps*",
        "*://www.google.cl/maps*",
        "*://www.google.cz/maps*",
        "*://www.google.dk/maps*",
        "*://www.google.ee/maps*",
        "*://www.google.fi/maps*",
        "*://www.google.fr/maps*",
        "*://www.google.de/maps*",
        "*://www.google.gr/maps*",
        "*://www.google.com.hk/maps*",
        "*://www.google.hu/maps*",
        "*://www.google.co.in/maps*",
        "*://www.google.com.ph/maps*",
        "*://www.google.ie/maps*",
        "*://www.google.co.il/maps*",
        "*://www.google.it/maps*",
        "*://www.google.co.jp/maps*",
        "*://www.google.li/maps*",
        "*://www.google.com.mx/maps*",
        "*://www.google.nl/maps*",
        "*://www.google.co.nz/maps*",
        "*://www.google.no/maps*",
        "*://www.google.pl/maps*",
        "*://www.google.pt/maps*",
        "*://www.google.ru/maps*",
        "*://www.google.com.sg/maps*",
        "*://www.google.co.za/maps*",
        "*://www.google.co.kr/maps*",
        "*://www.google.es/maps*",
        "*://www.google.se/maps*",
        "*://www.google.ch/maps*",
        "*://www.google.com.tw/maps*",
        "*://www.google.co.uk/maps*",
        "https://encrypted.google.com/maps*",
        "*://www.bing.com/maps*",
        "*://www.openstreetmap.org/*",
        "*://www.fullscreenmaps.co/*"
      ],
      "js": [
        "jquery.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "jid1-I1AHb505ZWPehw@jetpack"
    }
  }
}