Examine source code of wearewatched

{
  "manifest_version": 2,
  "name": "wearewatched",
  "version": "0.1.0",
  "description": "See which APIs fingerprint your device and which permissions sites silently request.",
  "permissions": [
    "<all_urls>"
  ],
  "browser_action": {
    "default_title": "wearewatched",
    "default_popup": "popup.html"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_start"
    }
  ],
  "web_accessible_resources": [
    "inject.js"
  ],
  "icons": {
    "48": "icon48.png",
    "128": "icon128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "wearewatched@extension",
      "strict_min_version": "142.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}