Cross-Platform Productivity App Development

I'm seeking an experienced app developer to create a cross-platform productivity app focused on task management.

Key Requirements:
- Core feature: Task management
- Platforms: iOS and Android
- User-friendly interface
- Secure data handling
- Offline functionality

Ideal Skills and Experience:
- Proven experience in cross-platform app development
- Strong background in UI/UX design
- Expertise in task management features
- Familiarity with data security protocols
- Excellent problem-solving skills

Please provide samples of similar work done.