Examine source code of TrackBlock – Email Tracker Blocker

{
  "manifest_version": 3,
  "name": "TrackBlock – Email Tracker Blocker",
  "short_name": "TrackBlock",
  "version": "2.0.2",
  "description": "Detect and block email tracking pixels in Gmail, Outlook, Yahoo Mail, and 15+ other email clients. Local-only analysis. Zero data collection.",
  "browser_specific_settings": {
    "gecko": {
      "id": "{08aeed65-d5f3-452d-85c1-ad8133c44b41}",
      "strict_min_version": "140.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    },
    "gecko_android": {
      "strict_min_version": "142.0"
    }
  },
  "icons": {
    "16": "icons/icon16.png",
    "32": "icons/icon32.png",
    "48": "icons/icon48.png",
    "96": "icons/icon96.png",
    "128": "icons/icon128.png"
  },
  "action": {
    "default_popup": "popup.html",
    "default_icon": {
      "16": "icons/icon16.png",
      "32": "icons/icon32.png",
      "48": "icons/icon48.png",
      "96": "icons/icon96.png",
      "128": "icons/icon128.png"
    },
    "default_title": "TrackBlock"
  },
  "background": {
    "scripts": [
      "src/background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "https://mail.google.com/*",
        "https://outlook.live.com/*",
        "https://outlook.office.com/*",
        "https://mail.yahoo.com/*",
        "https://mail.aol.com/*",
        "https://proton.me/*",
        "https://mail.proton.me/*",
        "https://mail.zoho.com/*",
        "https://www.fastmail.com/*",
        "https://app.fastmail.com/*",
        "https://mail.tuta.com/*",
        "https://www.icloud.com/*",
        "https://mail.com/*",
        "https://www.gmx.com/*",
        "https://mail.yandex.com/*",
        "https://mailfence.com/*",
        "https://startmail.com/*",
        "https://www.hushmail.com/*",
        "https://runbox.com/*",
        "https://posteo.de/*",
        "https://app.hey.com/*",
        "https://mail.titan.email/*",
        "https://mailbox.org/*"
      ],
      "js": [
        "src/trackers.js",
        "src/store.js",
        "src/tooltip.js",
        "src/scanner.js",
        "src/rowflagger.js",
        "src/content.js"
      ],
      "css": [
        "src/styles.css"
      ],
      "run_at": "document_idle",
      "all_frames": false
    }
  ]
}