iOS App Development with User Authentication

We need to create a mobile app (iOS & Android) for a housing company that offers rental homes and exclusive services to residents. The app will include a 24/7 Call Center (chat-based), service requests (moving, laundry, transfer, etc.), a city guide with news and local recommendations, a complaints & suggestions form with user identification, and a section with emergency contact numbers. Access will be limited to registered members via phone number or email.