Cross-Platform Social Networking App

I'm looking for an experienced mobile app developer to create a social networking application for my startup idea. The app should be compatible with multiple platforms, including iOS and Android.

Core Features:
- User Profiles
- Messaging System
- Activity Feed
- Interaction with other elements

Ideal Skills & Experience:
- Proficiency in both iOS and Android development
- Strong background in building social networking apps
- Experience with user authentication and real-time messaging
- Familiarity with designing engaging activity feeds

Please provide examples of similar work done.