Examine source code of Reflektive

{
  "name": "Reflektive",
  "version": "3.1.5",
  "manifest_version": 2,
  "description": "Pulse Recognition & Feedback",
  "icons": {
    "16": "images/icon-16.png",
    "128": "images/icon-128.png"
  },
  "default_locale": "en",
  "background": {
    "scripts": [
      "scripts/pulse.chrome.server.min.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "http://mail.google.com/*",
        "https://mail.google.com/*",
        "http://inbox.google.com/*",
        "https://inbox.google.com/*"
      ],
      "css": [
        "styles/main.css"
      ],
      "js": [
        "scripts/inboxsdk.js",
        "scripts/jquery.js",
        "scripts/jquery.resize.js",
        "scripts/pulse.chrome.client.min.js",
        "scripts/jsrsasign.js"
      ],
      "run_at": "document_end"
    }
  ],
  "options_page": "options.html",
  "permissions": [
    "http://*/*",
    "https://*/*"
  ],
  "web_accessible_resources": [
    "*.html",
    "images/*",
    "styles/*",
    "scripts/*",
    "oauth2/*"
  ],
  "externally_connectable": {
    "matches": [
      "*://mail.google.com/*",
      "*://inbox.google.com/*"
    ]
  }
}