Matt Wiebe

Kills the adminbar search field. I said that already, right?

Kill Adminbar Search

Do you hate the search portion in the adminbar? I often do, and kill it with this.

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.

Kill Adminbar Search vs Auto Hide Admin Bar