Examine source code of FB Page Unlocker

{
  "name": "FB Page Unlocker",
  "description": "Access and Unlock all Facebook Pages as a Guest, and without having to Login. Incl. Bypassing the Annoying Login Box!",
  "version": "1.0.3resigned1",
  "manifest_version": 2,
  "icons": {
    "16": "icons/icon16.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "permissions": [
    "*://*.facebook.com/*"
  ],
  "content_scripts": [
    {
      "matches": [
        "*://*.facebook.com/*"
      ],
      "css": [
        "FB.css"
      ]
    }
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "browser_action": {
    "default_icon": "icons/icon.png",
    "default_title": "Visit Facebook.com (Sample)"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "facebookrevealer@china-cheats"
    }
  }
}