Examine source code of Roll Together

{
  "name": "Roll Together",
  "version": "3.1.5",
  "description": "Synchronize Crunchyroll Videos",
  "background": {
    "scripts": [
      "service_worker.js"
    ],
    "persistent": false
  },
  "content_scripts": [
    {
      "all_frames": true,
      "matches": [
        "*://www.crunchyroll.com/*",
        "*://static.crunchyroll.com/*"
      ],
      "js": [
        "content_script.js"
      ]
    }
  ],
  "permissions": [
    "storage",
    "*://www.crunchyroll.com/*",
    "*://static.crunchyroll.com/*",
    "*://rt-sync.azurewebsites.net/*"
  ],
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "16": "images/get_started16.png",
      "32": "images/get_started32.png",
      "48": "images/get_started48.png",
      "128": "images/get_started128.png"
    }
  },
  "icons": {
    "16": "images/get_started16.png",
    "32": "images/get_started32.png",
    "48": "images/get_started48.png",
    "128": "images/get_started128.png"
  },
  "options_ui": {
    "page": "options.html",
    "open_in_tab": false
  },
  "manifest_version": 2,
  "applications": {
    "gecko": {
      "id": "let.us.roll.together@gmail.com",
      "strict_min_version": "109.0"
    }
  }
}