Examine source code of lecturio.de tools

{
  "manifest_version": 2,
  "name": "lecturio.de tools",
  "version": "0.3",
  "description": "lecturio.de tools (full width, picture in picture) for a better viewing experience",
  "icons": {
    "16": "img/icon16.png",
    "48": "img/icon48.png",
    "128": "img/icon128.png"
  },
  "browser_action": {
    "default_icon": {
      "19": "img/icon48.png",
      "38": "img/icon48.png"
    },
    "default_popup": "popup.html"
  },
  "permissions": [
    "storage"
  ],
  "options_ui": {
    "page": "popup.html",
    "open_in_tab": false
  },
  "content_scripts": [
    {
      "css": [
        "styles.css"
      ],
      "js": [
        "content.js"
      ],
      "matches": [
        "https://www.lecturio.de/*"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "lecturio-tools@joscha0.com"
    }
  }
}