Examine source code of Browser Time Trackers

{
  "manifest_version": 2,
  "name": "Browser Time Tracker",
  "version": "1.0",
  "description": "Tracks the time you spend in your browser and provides daily summaries.",
  "icons": {
    "48": "icon.png"
  },
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": "icon.png",
    "default_title": "Browser Time Tracker"
  },
  "permissions": [
    "storage",
    "idle"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": true
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{f8b9518a-51cd-4b02-9248-4ca8a2574e24}"
    }
  }
}