Examine source code of Blue Untick

{
  "browser_action": {
    "default_icon": "icons/untick-32.png",
    "default_title": "Blue Untick"
  },
  "content_scripts": [
    {
      "js": [
        "content.js"
      ],
      "matches": [
        "https://*.twitter.com/*"
      ],
      "run_at": "document_start"
    }
  ],
  "description": "Remove tick from Twitter Blue verified marks",
  "icons": {
    "48": "icons/untick-48.png",
    "96": "icons/untick-96.png"
  },
  "manifest_version": 2,
  "name": "Blue Untick",
  "permissions": [],
  "version": "1.0.1",
  "web_accessible_resources": [
    "untick.js"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{9e138f16-ea2a-4625-8a0f-523e6736b2ad}"
    }
  }
}