Examine source code of Grepl

{
  "manifest_version": 2,
  "name": "Grepl",
  "version": "0.1.0",
  "description": "Simple page search with regex support and highlighting",
  "permissions": [
    "activeTab",
    "tabs",
    "storage",
    "<all_urls>"
  ],
  "browser_action": {
    "default_title": "Grepl Search",
    "default_popup": "popup.html",
    "default_icon": {
      "16": "icon16.png",
      "48": "icon48.png",
      "128": "icon128.png"
    }
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ],
      "css": [
        "content.css"
      ]
    }
  ],
  "background": {
    "scripts": [
      "background-firefox.js"
    ]
  },
  "commands": {
    "toggle-search": {
      "suggested_key": {
        "default": "Ctrl+Shift+F"
      },
      "description": "Toggle Grepl Search"
    }
  },
  "web_accessible_resources": [
    "icon16.png",
    "icon48.png"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "grepl@example.com"
    }
  }
}