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

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

reveal_board();