Marcus (aka @msykes)

This plugin removes the admin bar completely from the public and admin areas of the website. Can be used either as a normal or MU plugin.
Upon activation/installation this works immediately. Nothing fancy, the admin bar is just not loaded anymore.
<h4>BuddyPress 1.1 Onwards</h4>
You can also add the following to your wp-config.php file and then you don’t need this plugin ( sniff ;( ) :
<pre><code>define( 'BP_DISABLE_ADMIN_BAR', false );
</code></pre>

Remove BuddyPress AdminBar

This plugin removes the admin bar completely from the public and admin areas of the…

Marcel Bootsman

Auto Hide Admin Bar makes the WordPress Toolbar disappear – and reappear when hovering the mouse pointer over the top of the browser window. 
You end up with a clean view of your site, and keep having access to the WordPress Toolbar. 
If you have any comments or questions, please use the <a href="https://wordpress.org/support/plugin/auto-hide-admin-bar" rel="ugc">support forum</a>.

Auto Hide Admin Bar

This plugin adds an auto-hide feature to the WordPress Admin Bar or Toolbar.

Remove BuddyPress AdminBar vs Auto Hide Admin Bar