Examine source code of FilterdIn

{
  "manifest_version": 2,
  "name": "FilterdIn",
  "version": "1.0",
  "description": "__MSG_extensionDescription__",
  "icons": {
    "16": "icons/filterdin-16.png",
    "48": "icons/filterdin-48.png",
    "128": "icons/filterdin-128.png"
  },
  "browser_action": {
    "default_icon": "icons/filterdin-48.png",
    "default_title": "FilterdIn",
    "default_popup": "popup.html"
  },
  "default_locale": "en",
  "permissions": [
    "activeTab",
    "storage",
    "tabs"
  ],
  "content_scripts": [
    {
      "matches": [
        "*://*.linkedin.com/*"
      ],
      "js": [
        "filterdin.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{df68fb3d-0f75-4b69-9cd3-a86b68ba1288}"
    }
  }
}