Examine source code of Two-Factor Authenticator

{
  "manifest_version": 2,
  "name": "Two-Factor Authenticator",
  "version": "1.0",
  "description": "Generate time-based 2FA codes in-browser.",
  "permissions": [
    "storage",
    "tabs"
  ],
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": "icon.png"
  },
  "icons": {
    "48": "icon.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{fb6cb8c7-d402-47cf-857d-d1709fa1f0de}"
    }
  }
}