Examine source code of Browser Time Tracker

{
  "manifest_version": 2,
  "name": "Browser Time Tracker",
  "version": "1.0",
  "description": "Tracks how much time you spend in your browser and provides daily and weekly summaries.",
  "permissions": [
    "storage",
    "tabs"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_popup": "popup.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{4147f01c-3e0b-4af4-850f-54d49d4b9f93}"
    }
  }
}