Examine source code of Pearltrees

{
  "name": "Pearltrees Extension",
  "description": "__MSG_extDescription__",
  "version": "8.1.4",
  "manifest_version": 2,
  "default_locale": "en",
  "icons": {
    "16": "image/icon16.png",
    "48": "image/icon48.png",
    "128": "image/icon128.png"
  },
  "permissions": [
    "*://*/*",
    "tabs",
    "contextMenus",
    "storage"
  ],
  "browser_action": {
    "default_icon": "image/chromeButton/in.png",
    "default_title": "Pearltrees",
    "default_popup": "popup.html"
  },
  "background": {
    "page": "background.html"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*/*"
      ],
      "js": [
        "script/chromeFirefoxContent.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "collector@broceliand.fr"
    }
  }
}