Examine source code of Popcorn - Ratings for Netflix

{
  "name": "Popcorn - Ratings for Netflix",
  "version": "0.3.1",
  "description": "Nondisruptive IMDb, Rotten Tomatoes, Metacritic and Douban ratings for Netflix shows.",
  "permissions": [
    "storage",
    "https://www.netflix.com/*",
    "https://movie.douban.com/*",
    "https://www.rottentomatoes.com/*",
    "*://unogs.com/*"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "browser_action": {
    "default_icon": {
      "16": "images/icon16-gray.png",
      "32": "images/icon32-gray.png"
    },
    "default_title": "Popcorn - Netflix show ratings"
  },
  "icons": {
    "16": "images/icon16.png",
    "32": "images/icon32.png",
    "48": "images/icon48.png",
    "64": "images/icon64.png",
    "128": "images/icon128.png"
  },
  "content_scripts": [
    {
      "matches": [
        "https://www.netflix.com/*"
      ],
      "js": [
        "content.js"
      ],
      "css": [
        "content.css"
      ]
    }
  ],
  "web_accessible_resources": [
    "images/*"
  ],
  "manifest_version": 2
}