Cross-Platform Productivity App Development

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

Essential Features:
- Task management
- Calendar integration
- Time tracking

Ideal Skills and Experience:
- Proficiency in both iOS and Android development
- Experience with productivity app features
- Strong UI/UX design skills
- Familiarity with app integration and databases

Looking for a developer who can bring innovative ideas and a user-friendly experience. Please provide a portfolio with similar projects.