IMPORTANT: If upgrading a MultiSite installation from Conditional Widgets 1.x to 2.x, you’ll need to visit the dashboard of each site in order to make Conditional Widgets function on that site. If you have a large number of sites, consider using this small plugin to assist you in doing so: https://github.com/MadtownLems/cets-multisite-dashboard-crawler
This plugin adds a form to each widget on the Widgets panel which allows users to choose which pages and/or categories the widget is either displayed on or hidden from.
For each widget, you can choose criteria to either SHOW or HIDE the widget, based on a number of categories. The interface is quite intuitive, and requires no knowledge of php or conditional tags.