Examine source code of SySwitch

{
  "name": "SySwitch",
  "description": "Easily switch between test/prod contexts by substituting it in the URL",
  "version": "0.0.1",
  "manifest_version": 2,
  "permissions": [
    "activeTab",
    "*://*/*"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": true
  },
  "icons": {
    "48": "images/syswitch_48.png"
  },
  "browser_action": {
    "default_icon": "images/syswitch_48.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{d7be71fe-0133-4f3a-9d38-d88397c5b54a}"
    }
  }
}