Examine source code of Privisibility

{
  "manifest_version": 2,
  "name": "Privisibility",
  "description": "Protect your privacy by masking PII on any web page.",
  "version": "0.2.0",
  "icons": {
    "16": "icons/16.png",
    "20": "icons/20.png",
    "24": "icons/24.png",
    "32": "icons/32.png",
    "48": "icons/48.png",
    "64": "icons/64.png",
    "128": "icons/128.png",
    "256": "icons/256.png"
  },
  "homepage_url": "https://privisibility.com",
  "permissions": [
    "storage"
  ],
  "browser_specific_settings": {
    "gecko": {
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      },
      "id": "{202aa91c-06d8-401e-b3d8-57eeb28a687d}"
    }
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_title": "Privisibility",
    "default_popup": "popup.html"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "run_at": "document_idle",
      "js": [
        "content-scripts/content.js"
      ]
    }
  ]
}