Examine source code of click2speech

{
  "manifest_version": 2,
  "name": "click2speech",
  "default_locale": "en",
  "description": "__MSG_extensionDescription__",
  "version": "2.1.4",
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content/content.js"
      ]
    }
  ],
  "permissions": [
    "http://*/",
    "https://*/",
    "storage"
  ],
  "background": {
    "scripts": [
      "background/background.js"
    ]
  },
  "options_ui": {
    "page": "options/index.html",
    "open_in_tab": true
  },
  "browser_action": {
    "default_icon": "img/iconOff32.png",
    "default_popup": "popup/popup.html"
  },
  "icons": {
    "16": "img/iconOn32.png",
    "128": "img/icon64.png"
  },
  "minimum_chrome_version": "47",
  "browser_specific_settings": {
    "gecko": {
      "id": "{961b86e9-adc2-43bc-bc8c-aa99ea2a047b}"
    }
  }
}