Examine source code of Remind

{
  "manifest_version": 2,
  "name": "Reminder",
  "version": "1.0",
  "description": "This is a reminder add-on which reminds you about the things you specify, provided some time.",
  "icons": {
    "48": "icon.png"
  },
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": "icon.png"
  },
  "permissions": [
    "notifications"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{c2fbc93b-02c2-4053-b788-9f955e1ced69}"
    }
  }
}