JSFiddle - React, Tailwind, and code Playground

HTML

<ul>
    <li class="app">App1</li>
    <li class="app">App2</li>
     <li class="app">App3</li> 
     <li class="app">App4</li> 
</ul>

<div id="newApp">Big App Interface</div>

CSS

.app {
    width: 32px;
    height: 32px;
    display: inline-block;
    background-color: blue;
    padding: 10px;
}

#newApp {
    height: 256px;
    width: 256px;
    background-color: red;
    display: none;
}

JavaScript

$('.app').fadeOut(1000, function() {
  $('#newApp').fadeIn(1000);
});