A very useful plugin

This plugin provides such an essential function (i.e. Showing or hiding widgets page-by-page) that I am really surprised that it isn’t a standard WordPress feature.

I have been using it to develop a new web site and it has worked flawlessly with but one exception: It does not seem to work or appear as an option on the one plugin widget (as opposed to theme widget) that I wanted to show/hide. I have found it useful for the other widgets, however.