Examine source code of Twitter Origifier

{
  "name": "Twitter Origifier",
  "version": "1.4resigned1",
  "manifest_version": 2,
  "description": "Makes twitter images their original resolution",
  "homepage_url": "https://nathanwentworth.co",
  "content_scripts": [
    {
      "matches": [
        "https://pbs.twimg.com/media/*"
      ],
      "js": [
        "origifier.js"
      ],
      "run_at": "document_end"
    }
  ],
  "permissions": [
    "activeTab"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{eaf526e2-6989-421a-8291-ef0410dda4f4}"
    }
  }
}