same day delivery app for malls

I'm looking to build a mobile utility app for both iOS and Android platforms.

Key Requirements:
- Experience in developing utility apps
- Proficiency in cross-platform mobile app development
- Strong UI/UX design skills
- Knowledge of backend integration and database management

Ideal Skills:
- Flutter or React Native expertise
- Familiarity with RESTful APIs
- Prior experience with app store deployments

Please provide portfolios and relevant experience.