Offline App Optimization and Visualization

I have created a small offline app and would like someone to optimize it. The app is designed to display connections between companies. I enter a company and employees, and I have several roles, such as managing directors with time periods, shareholders, and interpreters who were involved in the company’s formation.

The main issue I am having is with the visualization. I would like to create a company organigram in which the company with the most connections is placed in the center, and the companies with fewer connections are arranged outward around it. The connections should be labeled so that the structure is easy to understand. It should also be possible to move the diagram with the mouse, zoom in and out by scrolling, and use a search field to look up a company. The organigram is divided into people and companies.

Secondly, I would like the layout to look more modern and the buttons to be more visually appealing.

Please send me a quote. I have attached the files.

I can also make it sound more formal or more natural for sending to a developer.