Examine source code of HexagonAll for Twitter

{
  "name": "HexagonAll",
  "description": "Hexagonal profile pictures for everybody",
  "version": "1.0",
  "manifest_version": 2,
  "permissions": [
    "tabs"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "https://twitter.com/*"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_end"
    }
  ],
  "browser_action": {
    "default_icon": {
      "48": "/images/hexagon_48.png",
      "96": "/images/hexagon_96.png"
    },
    "default_title": "HexagonAll"
  },
  "icons": {
    "48": "/images/hexagon_48.png",
    "96": "/images/hexagon_96.png"
  }
}