Mobile App & Tool Development

I'm seeking an experienced developer to maintain and further develop my mobile app (iOS and Android) and online tool. The project requires working in Polish.

Key areas needing attention:
- User Interface Design: Improve the overall look and feel.
- Backend Functionality: Enhance and streamline server-side processes.
- Performance Optimization: Ensure the app runs smoothly and efficiently.

Requirements:
- Proficiency in both iOS and Android development.
- Strong skills in UI/UX design, backend development, and performance tuning.
- Fluent in Polish.

Ideal Skills:
- Mobile App Development (iOS & Android)
- UI/UX Design
- Backend Development
- Performance Optimization
- Polish Language Proficiency