Jess Mann

This plugin adds an additional admin page which shows you every registered 
widget, and allows you to deactivate any you do not want to appear. For 
example, when you are adding widgets to a sidebar, the Post Loop widget is 
usually not wanted, and just adds additional clutter you must sort through. On 
this widget’s admin page, simply click on the widgets you would like to 
disable, and then hit the “Save” button at the very bottom of the page!

Customize Widgets

Too many widgets cluttering up your wordpress install? This plugin allows you to hide unwanted widgets from the Appearance > Widgets panel, and any …

Aaron Holbrook

Small plugin to throw in mu-plugins that disables the WP Menu from the WordPress admin bar. I’ve found on some client sites that it poses more of a hindrance to have additional administrative options.

Remove WP Menu

Small plugin to throw in mu-plugins that disables the WP Menu from the WordPress admin bar. I've found on some client sites that it poses more of …

Customize Widgets vs Remove WP Menu