Examine source code of gvsavings

{
  "name": "gvsavings",
  "version": "0.18.1",
  "manifest_version": 2,
  "description": "__MSG_appDesc__",
  "default_locale": "ru",
  "applications": {
    "gecko": {
      "id": "gvs@erinome.net",
      "strict_min_version": "58.0"
    }
  },
  "permissions": [
    "storage",
    "*://gv.erinome.net/*"
  ],
  "options_ui": {
    "page": "options.html",
    "open_in_tab": false
  },
  "icons": {
    "16": "icon16.png",
    "32": "icon32.png",
    "48": "icon48.png",
    "128": "icon128.png"
  },
  "content_scripts": [
    {
      "js": [
        "loader.js"
      ],
      "matches": [
        "*://godville.net/superhero",
        "*://godvillegame.com/superhero"
      ]
    }
  ]
}