JSFiddle - React, Tailwind, and code Playground

HTML

<h1>Mobile device counter test</h1>
<span id="counter"></span>
<span id="timeOfUpdate"></span>

CSS

h1 {
   font-size: 24px;
   margin: 5px 5px 5px 5px;
   font-family: Tahoma;       
}

span {
   border: 1px #c0c0c0 solid;
   font-size: large;
   margin: 5px 5px 5px 5px;   
   font-family: Tahoma;    
   display: block;    
}

JavaScript

var n = 0;

function incrementTheThingy() {
    n = n + 1;
    $("#counter").text(n);
    $("#timeOfUpdate").text(new Date());
}

window.setInterval(incrementTheThingy, 500);