Barbershop Scheduling App Development

I need a comprehensive scheduling app for a barbershop/hairdresser, available on both iOS and Android. The app should support multiple user roles: Admin, Customer, and Staff/Barber.

Key Features:
- Scheduling: Recurring appointments, time slot customization, integrated calendar view.
- Customer Profile Management: Including before and after pictures, managing service preferences.
- Service List: Detailed list of services offered.
- Invoicing: Generate and manage invoices.
- Notifications: Schedule reminders and confirmation requests.
- Integration: WhatsApp for communication.

Ideal Skills & Experience:
- Mobile app development (iOS & Android)
- Experience with user role management
- Strong UI/UX design skills
- Backend development for data management and integrations
- Familiarity with WhatsApp API