notorioushttp

Allows developers to log variables, see the call stack, benchmark code; all to a logfile, so your page doesn’t get polluted with log messages. Each log message records the date and time, IP address, requested page, and file and line the log message came from, as well as the information to be logged.
The plugin has an options page which allows you to randomize the cookie and logfile, for security purposes; as well as turning logging on and off for a given user. (Via cookie.)
Documentation for the aaLog class can be found at the <a href="http://www.notoriouswebmaster.com/2013/07/01/aalog-a-logging-class-for-php/" rel="nofollow ugc">NotoriousWebmaster blog</a>.
Documentation for the aaLogWP plugin, which includes the aaLog class, can also be found at <a href="http://www.notoriouswebmaster.com/aalogwp-documentation/" rel="nofollow ugc">NotoriousWebmaster blog</a>, though on a different page.

aaLogWP

Allows developers to log variables, see the call stack, and benchmark code; all to a logfile, so your page won't get polluted with log messages.

shra

This plugin caches web requests and stores static html code. You can configure what urls do not to cache, what user shouldn’t be cached and ect.
After first web request plugin will create a cache of this requested webpage, and on second request your webserver will serve static html code instead of processing the comparatively heavier and more expensive WordPress PHP scripts.
It has some options to drive caching process.
You can:
<ul>
<li>… define filter by regular expressions pattern to exclude 
necessary urls from cache.</li>
<li>… fill user’s list to define who will not cached.</li>
<li>… do cache only for anonymous users.</li>
<li>… forcing rebuild cache on page/comment updating.</li>
<li>… setup cache timing.</li>
<li>… activate server confing boosters.</li>
</ul>
and etc.

Alpha Cache

Simple caching plugin that works on my WooCommerce store with standard settings.

Works

Caching plug-in. Easy to setup, free to use and fast in action.

aaLogWP vs Alpha Cache