Examine source code of Twingling

{
  "manifest_version": 2,
  "name": "Twingling",
  "version": "2.1.5resigned1",
  "description": "Analiza tus mensajes en whatsapp. Para partir haz click en el pomelo que aparece en la barra de navegación cuando visitas la página https://web.whatsapp.com/. Mira los tips en http://calafate.endesarrollo.cl/twingling/#tips",
  "homepage_url": "http://calafate.endesarrollo.cl/twingling",
  "developer": {
    "name": "marcelo alfaro",
    "url": "http://calafate.endesarrollo.cl/twingling"
  },
  "icons": {
    "48": "/img/pomelo-48.svg",
    "96": "/img/pomelo-96.svg"
  },
  "permissions": [
    "activeTab",
    "tabs"
  ],
  "background": {
    "scripts": [
      "/js/background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "*://web.whatsapp.com/*"
      ],
      "js": [
        "/js/jquery.min.js",
        "/js/jquery.mustache.js",
        "/js/pouchdb.js",
        "/js/pouchdb.memory.js",
        "/js/nouislider.js",
        "/js/wordcloud2.js",
        "/js/interfaz.js"
      ]
    }
  ],
  "page_action": {
    "default_icon": "/img/pomelo-op03.svg",
    "default_title": "Twingling 2.1.4a"
  },
  "web_accessible_resources": [
    "/img/pomelo-op03.svg",
    "/img/pomelo-op10.svg",
    "/img/pomelo-black.svg"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{f2040caa-7676-4af0-813e-9eaf9e24e8a8}"
    }
  }
}