gobanana

This plugin will output a list of your chosen categories and filter the posts on the fly using jQuery animation.
The setting pages allows you to select which categories should appear, whether or not to include jQuery (if you don’t already have it in the ) and a place to define the posts container. This should be either the class or id of the div that contains all the posts for filtering.
I am open to suggestions to improve the plugin !
<h3>Plugin Site</h3>
http://gobanana.ca/wp-filters

WP-Filters

A live post filtering plugin. Choose which categories to show in the filter and watch the post show/hide without reloading.

Philip Newcomer

Sometimes developers need to filter the output of a widget that does not have its own output filter built-in. This plugin provides a filter which will allow developers to filter any widget’s output, regardless of whether it has that capability natively or not.
This plugin was inspired by a similar filter in the <a href="https://wordpress.org/plugins/widget-logic/" rel="ugc">Widget Logic</a> plugin, and essentially duplicates that functionality, but with more flexibility.
Usage instructions are <a href="https://github.com/philipnewcomer/widget-output-filters" rel="nofollow ugc">on GitHub</a>.
This plugin is developed <a href="https://github.com/philipnewcomer/widget-output-filters" rel="nofollow ugc">on GitHub</a>, and is available as a <a href="https://packagist.org/packages/philipnewcomer/wp-widget-output-filters" rel="nofollow ugc">Composer package</a>.

Widget Output Filters

A library which enables developers to filter the output of any WordPress widget.

WP-Filters vs Widget Output Filters