Plugin – Widget logic

Plugin – Widget logic, gives every widget an extra control field called ”Widget logic” that lets you control the pages that the widget will appear on. The text field lets you use WP’s Conditional Tags, or any general PHP code. There is also an option to add a WordPress ’widget_content’ filter — this lets you tweak standard widgets to suit your theme without editing plugins and core code.
This is brilliant!

Link: https://wordpress.org/plugins/widget-logic/