Cross-Platform Mobile App Development

I need an experienced app developer to create a mobile app for both iOS and Android platforms. This project is urgent, and I require the app to be completed as soon as possible.

Ideal Skills and Experience:
- Proficiency in React Native or Flutter for cross-platform development
- Strong experience with both iOS and Android app development
- Knowledge of backend integration and API development
- Familiarity with app store submission processes for both platforms
- Ability to work quickly and efficiently to meet tight deadlines
- Strong problem-solving skills and attention to detail

Please provide examples of your previous work and an estimated timeline for completion.