Examine source code of Screen Time Tracker

{
  "manifest_version": 2,
  "name": "Screen Time Tracker",
  "version": "1.0",
  "description": "Track the amount of time spent on each website.",
  "permissions": [
    "storage",
    "webNavigation",
    "tabs"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": true
  },
  "browser_action": {
    "default_popup": "popup.html",
    "default_title": "Screen Time Tracker"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{b460e194-0378-4497-9dc9-b7c3cc67a4c5}"
    }
  }
}