Examine source code of dropout-progress

{
  "manifest_version": 3,
  "name": "dropout-progress",
  "version": "3.0.2",
  "browser_specific_settings": {
    "gecko": {
      "id": "{90e32c40-5b2a-42f5-92f0-ba2314b3ab5f}"
    }
  },
  "permissions": [
    "storage"
  ],
  "icons": {
    "128": "icon-128x128.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.dropout.tv/*"
      ],
      "js": [
        "player.js",
        "dropout-position.js"
      ]
    }
  ],
  "options_ui": {
    "page": "options.html"
  }
}