Examine source code of Domain Time Tracker

{
  "manifest_version": 2,
  "name": "Domain Time Tracker",
  "version": "1.0.2",
  "description": "Track time spent on specific domains",
  "browser_specific_settings": {
    "gecko": {
      "id": "domain-time-tracker@example.com"
    }
  },
  "permissions": [
    "storage",
    "tabs",
    "activeTab"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": "time-tracker-icon.svg"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "icons": {
    "48": "time-tracker-icon.svg",
    "96": "time-tracker-icon.svg"
  }
}