Examine source code of Proxy Switcher

{
  "browser_action": {
    "default_title": "Proxy switcher",
    "default_popup": "switcher.html",
    "browser_style": true,
    "default_icon": {
      "128": "half-world.svg"
    }
  },
  "description": "Easily switch between proxy settings.",
  "manifest_version": 2,
  "name": "Proxy Switcher",
  "permissions": [
    "proxy"
  ],
  "icons": {
    "128": "half-world.svg"
  },
  "version": "1.0",
  "browser_specific_settings": {
    "gecko": {
      "strict_min_version": "91.1.0",
      "id": "{6260dd0a-6de7-43eb-80e4-b0058e530968}"
    }
  }
}