How do you start making app UI as engineer?

As a design engineer I create my app’s UI by myself constantly searching for good references (ex. X, Figma, Mobbin). While web devs have access to numerous UI component libraries, the mobile app world seems to lack similar resources. I understand that mobile UIs are more personal and less standardized, but having customizable templates could still provide a helpful starting point.

This realization led me to develop an open-source iOS UI component library, designed to be easily integrated and customized to suit individual app needs.

What resources, tools, or approaches have you found valuable in creating effective and user-friendly interfaces?

GitHub repo https://github.com/mireabot/ExpensaroUIKit