Cross-Platform Productivity App Development

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

Essential features include:
- Task management
- Calendar integration
- Note-taking
- Artificial Intelligence
- Multi-API integration

The ideal candidate should have:
- Proven experience in mobile app development for both iOS and Android.
- Strong background in building productivity tools.
- Expertise in AI and API integrations.
- Familiarity with task management and calendar functionalities.

Please provide examples of similar work done and any relevant qualifications. Looking forward to your proposals!