Examine source code of SF Org Manager (Free)

{
  "manifest_version": 3,
  "name": "SF Org Manager (Free)",
  "version": "1.1.0",
  "description": "Manage all your active Salesforce orgs. Detects sessions automatically, displays details, and opens any org in one click.",
  "action": {
    "default_popup": "popup.html",
    "default_title": "SF Org Manager",
    "default_icon": {
      "16": "icons/icon16.png",
      "32": "icons/icon32.png",
      "48": "icons/icon48.png",
      "128": "icons/icon128.png"
    }
  },
  "icons": {
    "16": "icons/icon16.png",
    "32": "icons/icon32.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "permissions": [
    "storage",
    "cookies"
  ],
  "host_permissions": [
    "https://*.salesforce.com/*",
    "https://*.salesforce-setup.com/*",
    "https://*.force.com/*"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "sf-org-manager-free@brandonrorie.com",
      "strict_min_version": "109.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}