Examine source code of Facebook Auto Invite

{
  "manifest_version": 2,
  "name": "facebook Auto Invite",
  "version": "1.2",
  "description": "This extension lets you invite all the people who liked your post on Facebook to like your page or join your group. It saves you time and effort by automating the invitation process. Just install the extension, go to your post, and click the extension icon. You can choose to invite everyone who liked your post, or filter by friends or non-friends. You can also set a delay between each invitation to avoid Facebook limits. Try it now and grow your audience with ease!",
  "icons": {
    "48": "icons/fb_inv_icon2.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.facebook.com/*"
      ],
      "js": [
        "fb_inv_all.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "fb_inv_all@gitvid.com"
    }
  }
}