Cross-Platform App Development

I'm seeking an experienced app developer to create an application for both iOS and Android platforms.

Key Requirements:
- Expertise in developing cross-platform mobile apps
- Proficiency in both iOS and Android environments
- Experience in either e-commerce, social networking, or productivity tools apps

Ideal Skills:
- Strong knowledge of Flutter or React Native
- Familiarity with backend integration
- UI/UX design skills are a plus

Please provide portfolios and relevant experience.