BABI Health Diagnostic App Development

I'm looking for an experienced mobile app developer to create the BABI Health Diagnostic app. The primary purpose of this app is to facilitate booking appointments. The app will need to support multiple user roles including Patients, Doctors, and Administrators.

Key Requirements:
- User-friendly interface for all user roles
- Secure login and profile management
- Appointment booking system with calendar integration
- Notifications and reminders for upcoming appointments
- Admin dashboard to manage appointments and users

Ideal Skills and Experience:
- Proven experience in mobile app development
- Strong UI/UX design skills
- Familiarity with secure authentication protocols
- Experience with calendar and notification APIs
- Background in healthcare app development is a plus

Please provide a portfolio showcasing similar work and an estimated timeline for completion.