Expert Connect: Multi-Modal Mobile Application

I'm seeking an experienced mobile app developer to create an Android and iPhone app. The application will need to allow users to search for experts by location, skill set, and experience.

Key Features:
- Multi-modal Communication: Users should be able to connect with experts via chat, voice call, and video call.
- Payment Gateway: The app will need to integrate a secure payment gateway for service transactions.

Ideal Skills and Experience:
- Experience in creating secure mobile applications
- Proficiency in Android and iOS development
- Knowledge of various communication modalities (chat, voice calls, video calls)
- Experience with payment gateway integration
- Understands user interface and experience for expert-search apps
- Could provide maintenance and updates after app launch