Cross-Platform Text Messaging App Development

I'm looking for an experienced mobile application developer to create a text messaging app for both iOS and Android platforms.

Key requirements include:
- Core functionality to send and receive messages
- User authentication via email and password

The ideal candidate should have:
- Proven experience in developing cross-platform mobile applications
- Strong expertise in secure user authentication
- Familiarity with messaging protocols and real-time data transmission

Please include relevant experience and portfolio. Looking forward to your proposals!