I need a comprehensive member management system for a swim and tennis club. The system should work on web, iOS, and Android platforms. Key functionalities include: - Billing: Manage all financial transactions. - Program Registration: Allow members to sign up for various programs. - POS System: Handle purchases and sales within the club. User roles should include: - Members: Access to their profiles, billing, and program registration. - Staff/Admins: Manage the entire system, oversee transactions, and handle registrations. - Guests: Limited access for non-members. Ideal skills and experience: - Strong background in developing cross-platform applications. - Experience with billing and POS system integration. - Familiarity with user role management in applications.