Healthcare Services App Development

I'm looking to hire an experienced app developer to create a comprehensive healthcare services application for my company. The app should be available on both iOS and Android platforms.

Key Features:
- Health tracking
- Online booking
- Chat with doctor
- Additional services to be agreed upon

User authentication is required via email.

Ideal Skills and Experience:
- Proficiency in mobile app development for both iOS and Android
- Experience in integrating health tracking and telemedicine features
- Strong background in secure user authentication processes
- Familiarity with healthcare regulations and data privacy laws

Please share relevant portfolio and experience.