JSFiddle - React, Tailwind, and code Playground

HTML

<ul id="sample">
    <li>First Item</li>
    <li>Second Item</li>
    <li>Third Item</li>
    <li>Fourth Item</li>
    <li>Fifth Item</li>
    <li>Sixth Item</li>
    <li>Nth Item</li>
</ul>

CSS

#sample li{
    display: none;
}

JavaScript

$.fn.show_items = function(duration, delay) {
    return this.each(function(index) {
        var thisLi = $(this);
        setTimeout(function(){
            thisLi.fadeIn(duration);
        }, delay * index);
    });
};

// function usage
$('#sample li').show_items(50, 100);