isaacchapman

The Htaccess Secure Files plugin can only be activated on Apache web servers with mod_rewrite enabled, and will automatically raise an error upon activation if this is not the case.
The Htaccess Secure Files plugin allows for setting files to be accessible only to visitors who have a specified IP address or <a title="WordPress role or capbility" href="https://codex.wordpress.org/Roles_and_Capabilities" rel="nofollow ugc">WordPress role or capability</a>. By using <a title=".htaccess files" href="http://en.wikipedia.org/wiki/Htaccess" rel="nofollow ugc">.htaccess files</a> to secure the content instead of a separate directory outside the web root, WordPress’s native media library functionality can be used to upload secure files and link to them from within the visual editor.
By default all built-in WordPress roles will be allowed to access content that is marked as secure. The Settings -> Secure Files admin screen controls which roles, capabilities, and IP addresses are allowed to view or download secured files. If a custom role or capability is desired, there are several <a title="WordPress plugins" href="https://wordpress.org/extend/plugins/search.php?q=roles+capabilities" rel="ugc">WordPress plugins</a> capable of creating and editing roles and capabilities.
Any visitor that matches any selected role, capability, or IP address will be allowed to access secured files.
This plugin works by creating a .htaccess files in the directory of each secured file. If you manually edit the .htaccess file and it becomes corrupt (a 500 Internal Server Error is the most likely symptom), I recommend deleting the .htaccess file and then edit and save each secured item in the media library.

Htaccess Secure Files

Allows securing files in WP's media library to be only accessible to users with specific roles, capabilities, or IP addresses.

Stefano Lissa

Hyper Cache is a cache plugin specifically written to get the maximum speed for your WordPress blog.
It can be used in low resources hosting as well on high end servers.
Hyper Cache is purely PHP and works on every blog: no complex configurations are needed and when you deactivate it no stale settings are left around.
NOTE
Mobile detection server side and serving different content to mobile and desktop device is now obsolete. 
Every modern WP theme deals with mobile/desktop contexts using the media queries, progressive enhancement and so on. 
So I don’t see the need to keep the mobile/desktop cache separation and all the overhead in the plugin. The feature will be removed as version 3.5.
Short list of features:
<ul>
<li>Mobile aware: double cache for desktop and mobile site versions</li>
<li>HTTPS ready</li>
<li>Mobile theme switch option: change the theme on mobile device detection</li>
<li>Able to serve expired pages to bots to increase the perceived blog speed by bots</li>
<li>Manages compression even on the fly for non cached pages</li>
<li>Lots of configurable bypasses: matching cookies, matching urls, user agents, …</li>
<li>Comments aware: is able to serve cached pages even to visitors who commented the blog (perfect for blog with great readers paritipation)</li>
<li>Cache folder can be moved outside your blog space to exclude it from backups</li>
<li>Controls over cache cleaning on blog events (post edited, comments, …)</li>
<li>Autoclean to controls the cache used disk space</li>
<li>CDN support</li>
<li>Other special options</li>
<li>Response header signature to check the working status</li>
<li>bbPress specific integration</li>
</ul>
More can be read on the <a href="https://www.satollo.net/plugins/hyper-cache" rel="nofollow ugc">Hyper Cache official page</a>.
You can further optimize the blog installing <a href="https://wordpress.org/plugins/autoptimize/" rel="ugc">Autoptimize</a> which cleans up the HTML, minifies and concatenates CSS and JavaScript.
Other plugins by Stefano Lissa:
<ul>
<li><a href="https://www.thenewsletterplugin.com" rel="nofollow ugc">Newsletter</a></li>
<li><a href="https://www.satollo.net/plugins/header-footer" rel="nofollow ugc">Header and Footer</a></li>
<li><a href="https://www.satollo.net/plugins/include-me" rel="nofollow ugc">Include Me</a></li>
<li><a href="http://www.satollo.net/plugins/thumbnails" rel="nofollow ugc">Thumbnails</a></li>
</ul>

Hyper Cache

Super fast, not overly complicated but with enough settings to customize for any set up. Most importantly: works like a charm on VPS!

THE caching plugin

Really well coded plugin, improved pagespeed for google from 86 to 93 compared to lightspeed cache. Simple and reliable.

Simply faster

Hyper Cache is a performant and easy to configure cache system for WordPress.

Htaccess Secure Files vs Hyper Cache