Show Widgets Only on Certain Page Types
Adds a "Show on" setting to every classic widget, so you can limit it to the homepage, single posts, blog and archive pages, or everywhere except those.
Snippet Library
Widgets snippets for WordPress
Snippets for widgets and sidebars: restore the classic widget screen, register new widget areas, remove default widgets and allow shortcodes in text widgets. For classic themes and sites that still lean on sidebars.