Examine source code of DeXify Twitter

{
  "manifest_version": 2,
  "name": "DeXify Twitter",
  "version": "1.0",
  "description": "Restores Twitter's bird-themed branding.",
  "icons": {
    "48": "icons/deXify-48.png"
  },
  "content_scripts": [
    {
      "js": [
        "deXify.js"
      ],
      "matches": [
        "*://twitter.com/*"
      ],
      "run_at": "document_end"
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{b22cce29-424f-4a52-a431-784208bb398b}"
    }
  }
}