You haven't provided any specification or requirements for the web app. Without knowing what functionality, features, or purpose the app should have, I cannot generate the appropriate code. 

Please provide the specification or requirements for the web app, including:

1. Purpose/goal of the app
2. Desired features and functionality
3. Any specific UI/UX requirements
4. Data handling requirements
5. Any other relevant specifications

Once you share these details, I can provide a complete, working single-page application code that meets your needs.