Examine source code of Live <-> Dev swapper

{
  "manifest_version": 2,
  "name": "Live <-> Dev swapper",
  "version": "1.0.2",
  "author": "Dominik Hitschmann",
  "description": "Swap from live url to localhost-url and backword with one click",
  "icons": {
    "32": "img/logo.png"
  },
  "browser_action": {
    "default_icon": {
      "32": "img/logo-off.png"
    }
  },
  "permissions": [
    "activeTab",
    "<all_urls>",
    "storage"
  ],
  "background": {
    "scripts": [
      "src/background.js"
    ]
  },
  "options_ui": {
    "page": "src/settings/index.html",
    "open_in_tab": true
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{9b122766-0827-4066-80ce-93621f869103}"
    }
  }
}