JSFiddle - React, Tailwind, and code Playground

HTML

<div>Test</div><div>Test</div><div>Test</div><div>Test</div><div>Test</div><div>Test</div>
<div>Test</div><div>Test</div><div>Test</div><div>Test</div><div>Test</div><div>Test</div>
<div>Test</div><div>Test</div><div>Test</div>

CSS

.invisible { display: none; }

JavaScript

function reveal_board() {
    $("div").each(function(index) {        
        var that = this;
        var t = setTimeout(function() { 
            $(that).removeClass("invisible"); 
        }, 500 * index);        
    });
}

$('div').addClass('invisible');

reveal_board();