Examine source code of PeopleAdder

{
  "name": "PeopleAdder",
  "version": "7.5.5resigned1",
  "manifest_version": 2,
  "description": "PeopleAdder",
  "icons": {
    "16": "images/icon-16.png",
    "38": "images/icon-38.png",
    "48": "images/icon-48.png",
    "96": "images/icon-96.png",
    "128": "images/icon-128.png"
  },
  "page_action": {
    "default_icon": "images/icon-38.png",
    "default_title": "PeopleAdder",
    "default_popup": "popup.html"
  },
  "background": {
    "scripts": [
      "scripts/background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "http://hiringsolved.com/*/*",
        "https://hiringsolved.com/*/*",
        "http://www.facebook.com/*/*",
        "https://www.facebook.com/*/*",
        "http://twitter.com/*/*",
        "https://twitter.com/*/*",
        "http://*.linkedin.com/*/*",
        "https://*.linkedin.com/*/*"
      ],
      "js": [
        "scripts/jquery-2.1.1.min.js"
      ],
      "run_at": "document_end"
    }
  ],
  "permissions": [
    "tabs",
    "webNavigation",
    "http://*.linkedin.com/*/*",
    "https://*.linkedin.com/*/*",
    "http://twitter.com/*/*",
    "https://twitter.com/*/*",
    "http://www.facebook.com/*/*",
    "https://www.facebook.com/*/*",
    "http://hiringsolved.com/*/*",
    "https://hiringsolved.com/*/*",
    "https://apps.jobadder.com/*/*"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "@jobadder-for-social-1"
    }
  }
}