Examine source code of Git Tab Viewer

{
  "manifest_version": 2,
  "name": "GitTabViewer",
  "version": "1.4",
  "description": "Views a custom set tab spaces for github editor.",
  "icons": {
    "128": "icon.png"
  },
  "content_scripts": [
    {
      "run_at": "document_end",
      "matches": [
        "https://github.com/*/*",
        "https://gist.github.com/*/*",
        "https://raw.githubusercontent.com/*/*"
      ],
      "js": [
        "gittab.js"
      ]
    }
  ],
  "permissions": [
    "https://github.com/*/*",
    "https://gist.github.com/*/*",
    "https://raw.githubusercontent.com/*/*"
  ],
  "browser_action": {
    "default_icon": "icon.png",
    "default_title": "Git Tab Viewer",
    "default_popup": "gittab.html"
  }
}