Android Productivity App Development

I'm looking for an experienced Android developer to create a productivity app focused on task management. The app will primarily feature to-do lists.

Key Requirements:
- User-friendly interface for creating and managing to-do lists
- Ability to set deadlines, priorities, and reminders
- Option to categorize tasks by different projects or topics
- Syncing capabilities across multiple devices
- Secure user authentication and data protection

Ideal Skills:
- Proven experience in Android app development
- Strong UI/UX design skills
- Expertise in task management functionalities
- Familiarity with secure authentication methods
- Prior experience with productivity apps is a plus

Please provide examples of similar projects you have completed.