Examine source code of Retrofy

{
  "manifest_version": 2,
  "name": "Retrofy",
  "version": "1.1resigned1",
  "description": "",
  "icons": {},
  "permissions": [
    "tabs"
  ],
  "content_scripts": [
    {
      "exclude_matches": [
        "*://developer.mozilla.org/*"
      ],
      "matches": [
        "*://*/*"
      ],
      "css": [
        "assets/css/bootstrap.min.css",
        "assets/css/extra.css"
      ],
      "js": [
        "assets/js/retrofy.js"
      ]
    }
  ],
  "web_accessible_resources": [
    "assets/css/*.css",
    "assets/images/*.png"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{0105d641-662f-420b-aba1-afa5a584067a}"
    }
  }
}