Web App Enhancement and Android Integration

I'm looking for an experienced developer to add some crucial functions to my nearly complete web app and to create an Android app based on it.

Key Requirements:
- Add user authentication (email/password login).
- Implement a notifications system (email notifications).
- Android app development mirroring the web app's functionality.

Ideal Skills and Experience:
- Proficiency in web and Android app development.
- Experience with user authentication and notification systems.
- Strong knowledge of security practices for login systems.

Please provide examples of similar work done and your approach to ensure a smooth integration.