Examine source code of Browser Time Beta

{
  "manifest_version": 2,
  "name": "Browser Time Beta",
  "version": "1.7.1",
  "description": "Displays the current time and temperature so it's present at all times.",
  "permissions": [
    "storage",
    "https://tl1.us/*",
    "<all_urls>"
  ],
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ],
      "css": [
        "content.css"
      ],
      "run_at": "document_end"
    }
  ],
  "options_page": "options.html",
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "icons": {
    "16": "icon16.png",
    "48": "icon48.png",
    "128": "icon128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "browser-time-beta1@xtlab.net",
      "strict_min_version": "126.0"
    }
  }
}