Examine source code of Where to Stream

{
  "manifest_version": 2,
  "name": "Where to Stream",
  "short_name": "WhereToStream",
  "version": "1.5",
  "description": "Find out if a certain movie or TV show is available for streaming in your country.",
  "content_scripts": [
    {
      "matches": [
        "https://www.imdb.com/*",
        "https://www.metacritic.com/*",
        "https://www.rottentomatoes.com/*",
        "https://letterboxd.com/*",
        "https://www.cinemagia.ro/*",
        "https://www.crunchyroll.com/*",
        "https://myanimelist.net/*"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_idle"
    }
  ],
  "browser_action": {
    "default_popup": "main.html",
    "default_icon": {
      "16": "images/icon16.png",
      "32": "images/icon32.png",
      "48": "images/icon48.png",
      "128": "images/icon128.png"
    }
  },
  "icons": {
    "16": "images/icon16.png",
    "32": "images/icon32.png",
    "48": "images/icon48.png",
    "128": "images/icon128.png"
  },
  "permissions": [
    "activeTab",
    "storage",
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "web_accessible_resources": [
    "images/*.png"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "wheretostream@example.com"
    }
  }
}