JSFiddle - React, Tailwind, and code Playground

HTML

<div class="blueDiv toBeFaddedIn"></div>
<div class="blueDiv toBeFaddedIn"></div>
<div class="blueDiv toBeFaddedIn"></div>
<div class="blueDiv toBeFaddedIn"></div>
<div class="blueDiv toBeFaddedIn"></div>

CSS

.blueDiv {
    background-color: blue;
    height:50px;
    width: 50px;
    display: none;
    
}

JavaScript

function sequentialFadeIn(selectorText, speed, display, callBack) {

    display = typeof display !== 'undefined' ? display : "block";

    function helper() {
        if ($(selectorText).is(":not(.alreadyFadedIn)")) {
            nextElementToFadeIn = $(selectorText).not(".alreadyFadedIn").first();
            nextElementToFadeIn.fadeIn(speed, function() {
                $(this).addClass("alreadyFadedIn");
                helper();
            }).css("display", display);
        } else {
            callBack(selectorText);
        }
    }
    helper();




}
sequentialFadeIn(".toBeFaddedIn", "fast", "inline-block", function cleanUp(selectorText1) {
    $(selectorText1).removeClass("alreadyFadedIn");
    console.log("Clean up has been performed.");
    console.log("Selector text:" + selectorText1);
});