rfair404

In the multisite context, creating widgets that are used throughout all of the sites in a network can be difficult and painstaking (at best). 
This plugin gives network administrators the ability to create “fallback widgets” that will be used as the default unless over-ridden by individual sites.
How the plugin works
<ul>
<li>When a widget is created on the “main site” (e.g. site ID 1) the output is cached.</li>
<li>When a sites other than the “main site” (e.g. site ID != 1) call a sidebar that doesn’t have any active widgets, the cached output from the main site will be used.</li>
<li>The plugin may not (read as “probably won’t”) work with highly dynamic widgets</li>
<li>This is the initial release, so please try it out before you use it in a live site.</li>
</ul>

Network Sidebar Widgets

Enables Multisite Networks to create "fallback" widgets that can be used across-network when sites don't have any widgets.

nierdz

Flush OPcache
<ul>
<li>creates a button in admin bar to flush OPcache</li>
<li>flush only files in WordPress absolute path</li>
<li>individual or bulk file invalidation</li>
<li>support both memory and file caching</li>
<li>support multisite</li>
</ul>
OPcache Statistics
<ul>
<li>memory, hits, strings and keys statistics</li>
<li>directives, functions and general informations</li>
<li>list all files</li>
<li>fully responsive</li>
</ul>
WP CLI ready
<ul>
<li>add flush-opcache command to flush cache with cli: <code>wp flush-opcache flush</code></li>
<li>don’t forget to add <code>opcache.enable_cli=1</code> to your PHP configuration</li>
</ul>
There are three tabs in admin page under Tools:
<ul>
<li>General settings: plugin settings</li>
<li>Statistics: responsive dashboard about OPcache statistics</li>
<li>Cached files: list of cached files with the possibility of invalidating them</li>
</ul>

WP OPcache

works great

Bast OPCache Manager for WordPress

Manage OPcache inside your WordPress admin dashboard.

Network Sidebar Widgets vs WP OPcache