I find that there are 2 UI components for React Native which are mostly used. I want to use one of them. Which one of them is more easy to use and customizable ?
Currently, there are 3 main UI libraries:
Shoutem UI components are actually only one part of Shoutem UI Toolkit, which includes:
UI components come with the predefined beautiful design, so creating good looking applications is as easy as simply c/p-ing the component's code. However, they can be fully customized with a theme from one place, so you can achieve the separation of concerns for your components. Animations can be used in similar matter, too.
To see which kind of UI components are there, include <Examples>
components in your screen, as described here.
React Native Elements simplify the usage of common components in React Native. Native Base does that too, allows you to customize them and has a better documentation than React Native Elements.
Disclaimer: I work at Shoutem