Examine source code of Listening Back

{
  "name": "Listening Back",
  "version": "1.0.2",
  "manifest_version": 2,
  "description": "This extension plays a synth sound whenever a cookie is written, overwritten or deleted.",
  "homepage_url": "http://jasmineguffond.com/",
  "icons": {
    "16": "icons/icon16.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "applications": {
    "gecko": {
      "id": "bat.pub@com.jasmineguffond.listeningback"
    }
  },
  "browser_action": {},
  "default_locale": "en",
  "background": {
    "scripts": [
      "js/timbre.js",
      "src/bg/background.js"
    ],
    "persistent": true
  },
  "permissions": [
    "storage",
    "cookies",
    "tabs",
    "http://*/*",
    "https://*/*"
  ],
  "options_ui": {
    "page": "options.html",
    "browser_style": true
  }
}