Bootstrap can be used for fast mobile development. response display classes can be used to hide or display elements based on device.
In Bootstrap 5 the .d-none class is used or one of the .d-{sm,md,lg,xl,xxl}-none is used for any responsive screen variant.
Here is a basic example that shows an element only displaying on smaller devices such as mobile phones and tablets:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>wecode101 responsive bootstrap 5</title>
<link href="https://cdn.jsdelivr.net/npm/bootstrap@5.0.2/dist/css/bootstrap.min.css" rel="stylesheet" integrity="sha384-EVSTQN3/azprG1Anm3QDgpJLIm9Nao0Yz1ztcQTwFspd3yD65VohhpuuCOmLASjC" crossorigin="anonymous">
</head>
<body>
<div class="mt-5 container">
<h1>display content on smaller screens</h1>
<div class="mt-3 d-block d-sm-block d-md-block d-lg-none d-xl-none d-xxl-none">show on small screen</div>
</div>
</body>
</html>