Christmas Lights Service Mock-Up App

I need a cross-platform app (iOS and Android) developed. The primary function of this app will be a design mock-up tool for my Christmas Lights services.

Key Features:

- A user-friendly, intuitive drag-and-drop interface that allows easy creation of light designs.

- A diagram annotation tool that utilizes straight lines for precise placements.

Ideal Skills:

- Proficiency in cross-platform mobile app development.

- Previous experience with implementing design mock-up tools within apps.

- Understanding of creating engaging, user-friendly interfaces.

Please note, the app should not include a customer booking system or a price estimator. The focus should solely be on the design mock-up tool.