Cross-Platform Messaging App Development

I'm looking for an experienced app developer to create a messaging application for both iOS and Android platforms. The core functionality will be text messaging and sharing pictures.

Key requirements:
- Development for both iOS and Android
- Core features: Text messaging and picture sharing
- User-friendly interface
- Secure and reliable performance

Ideal skills and experience:
- Proficiency in mobile app development for iOS and Android
- Strong background in building messaging applications
- Expertise in UI/UX design
- Knowledge in implementing secure data transmission and storage

Please provide examples of similar work done. Looking forward to your bids!