<div class="well clearfix">
    <textarea class="form-control"></textarea><br/>
    <button class="btn btn-primary pull-right">Tweet</button>
  </div>

External CSS

  1. https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/css/bootstrap.min.css

External JavaScript

  1. https://code.jquery.com/jquery.min.js
  2. https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/js/bootstrap.min.js