Cross-Platform Mobile App UI/UX Design

I'm seeking a seasoned UI/UX designer to create a high-fidelity design for a new mobile app. This app will be aimed at both iOS and Android platforms, hence a solid understanding of the design guidelines and best practices for both systems is crucial.

Key Responsibilities:
- Design a user-friendly, engaging interface for a new mobile app.
- Create high-fidelity mockups that can guide the development team.
- Ensure the design is in line with iOS and Android's respective design principles.

Ideal Skills and Experience:
- Proven experience in designing mobile applications.
- Strong portfolio of cross-platform UI/UX designs.
- Proficiency in design tools such as Sketch, Figma, or Adobe XD.
- Understanding of usability and user experience principles.