Examine source code of Reminder Manager v2

{
  "manifest_version": 2,
  "name": "Reminder Manager",
  "version": "1.0",
  "description": "Create and manage reminders.",
  "permissions": [
    "storage"
  ],
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "48": "icons/icon.png"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{6caa575c-ff45-46a8-9ba8-856f55138d4a}"
    }
  }
}