Examine source code of url-rotation

{
  "manifest_version": 2,
  "name": "url-rotation",
  "version": "0.3.0",
  "author": "NicoVIII",
  "description": "This addon allows automatic rotating through a set of configured urls. Especially useful for screens which should show different websites for e.g. statistics.",
  "homepage_url": "https://github.com/NicoVIII/url-rotation-browser-extension",
  "permissions": [
    "tabs"
  ],
  "browser_action": {
    "default_icon": "assets/icons/play-32.png",
    "default_title": "Url Rotation"
  },
  "background": {
    "scripts": [
      "dist/background.js"
    ]
  },
  "options_ui": {
    "browser_style": true,
    "open_in_tab": true,
    "page": "assets/html/options.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{da1b1113-1976-4660-bcf3-78a6f28f93e6}"
    }
  }
}