Examine source code of Formlet

{
  "manifest_version": 2,
  "name": "Formlet",
  "description": "__MSG_extensionDescription__",
  "version": "2.1resigned1",
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "formlet.js"
      ]
    }
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "options_ui": {
    "page": "options/options.html",
    "browser_style": true
  },
  "permissions": [
    "activeTab",
    "bookmarks",
    "contextMenus",
    "notifications",
    "storage"
  ],
  "icons": {
    "16": "icons/formlet-16.png",
    "32": "icons/formlet-32.png",
    "48": "icons/formlet-48.png"
  },
  "applications": {
    "gecko": {
      "id": "formlet@preneta.pl"
    }
  },
  "default_locale": "en_US"
}