Mobile App Development

I'm looking for an experienced app developer to create a mobile application.

Key Requirements:
- Develop a mobile app
- Experience with both iOS and Android platforms is preferable
- Expertise in either e-commerce, social networking, or utility/tools apps

Ideal Skills and Experience:
- Proficiency in mobile app development languages and frameworks
- Strong UI/UX design skills
- Experience with backend integration and database management
- Familiarity with app store submission and guidelines

Please provide a portfolio with similar projects and estimated timelines.