Examine source code of HangHub

{
  "name": "HangHub",
  "version": "1.0.5",
  "description": "HangHub allows you to see who is viewing or commenting on the same GitHub issue or pull request as you in real time.",
  "permissions": [
    "activeTab",
    "tabs",
    "storage",
    "*://hanghub.cksource.com/*"
  ],
  "content_scripts": [
    {
      "matches": [
        "https://github.com/*"
      ],
      "js": [
        "index.js"
      ]
    }
  ],
  "icons": {
    "16": "images/icon16.png",
    "48": "images/icon48.png",
    "128": "images/icon128.png"
  },
  "browser_action": {
    "default_icon": "images/icon128.png",
    "default_popup": "popup.html",
    "default_title": "HangHub"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "hanghub@cksource.com"
    }
  },
  "manifest_version": 2
}