Multi-Functional Mobile App Development

I need an experienced app developer to create a comprehensive mobile application available on both iOS and Android platforms.

The app should include the following features:
- Messaging: (Please specify the type of messaging features you can provide: text, voice, video)
- Shared Calendar: For event scheduling and reminders
- Journal: Personal entry space
- Expenses Tracker: Log and manage expenses
- Member Area: Access to exclusive content
- Payment Portal: Secure transactions for membership fees

User authentication should be via email and password.

Ideal skills and experience:
- Proficiency in mobile app development for iOS and Android
- Experience with secure user authentication
- Strong background in integrating messaging systems and payment portals
- UI/UX design skills for a user-friendly interface
- Expertise in calendar, journaling, and expense tracking functionalities

Looking forward to your proposals!