Forces all logged in users to stay on SSL connection. Guests are still served http. 
Just install and activate – all done!
<ul>
<li>NOTE: The ‘force_ssl_admin’ and ‘force_ssl_login’ directives in ‘wp-config.php’ are not needed while using this plugin.</li>
</ul>
<h3>Features</h3>
<ul>
<li>SSL Login</li>
<li>SSL enforced for entire logged-in session</li>
<li>SSL for Admin and front-end of site</li>
<li>No messing with ‘wp-config.php’ or ‘htaccess’ directives</li>
<li>Easy to use, just install and activate on any SSL equipped site – no configuration required</li>
<li>WordPress 3.5 compatible</li>
<li>Network/Multisite compatible – can be activated on any sites in the Network, individually – sites should have a valid SSL certificate</li>
<li>Buddypress compatible</li>
<li>WP-Super-Cache compatible</li>
<li>S2Member compatible</li>
<li>Bulletproof Security compatible</li>
<li>The ‘force_ssl_admin’ and ‘force_ssl_login’ directives in ‘wp-config.php’ are not needed while using this plugin.</li>
</ul>

SSL for Logged In Users

Forces all logged in users to stay on SSL connection

JS Morisset

A simple, safe, and reliable way to force HTTP URLs to HTTPS dynamically:
No setup required – simply activate the plugin to force HTTP URLs to HTTPS.
There are no plugin settings to adjust, and no changes are made to your WordPress configuration.
SIGNIFICANTLY FASTER than other popular plugins of this type:
Other well known plugins use <a href="https://secure.php.net/manual/en/function.ob-start.php" rel="nofollow ugc">PHP’s output buffer</a> to search & replace URLs in the rendered HTML, which is a technique that is error prone and negatively affects caching performance (as changes are not cached).
This plugin uses standard WordPress filters instead of PHP’s output buffer for maximum reliability, performance, caching compatibility, and uses 301 permanent redirects for best SEO results (<a href="https://en.wikipedia.org/wiki/HTTP_301" rel="nofollow ugc">301 redirects are considered best for SEO when moving from HTTP to HTTPS</a>).
Supports advanced proxy / load-balancing HTTP headers:
<ul>
<li><code>X-Forwarded-Proto</code> (aka <code>HTTP_X_FORWARDED_PROTO</code> server value)</li>
<li><code>X-Forwarded-Ssl</code> (aka <code>HTTP_X_FORWARDED_SSL</code> server value)</li>
</ul>
See <a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/X-Forwarded-Proto" rel="nofollow ugc">Web technology for developers > HTTP > HTTP headers > X-Forwarded-Proto</a> for more details.
<h4>Plugin Requirements</h4>
Your web server must already be configured with an SSL certificate and able to handle HTTPS connections. 😉

JSM Force HTTP to HTTPS / SSL – No Setup, Fast and Reliable

No setup required - simply activate to force HTTP URLs to HTTPS using native WordPress filters and permanent redirects for best SEO.

SSL for Logged In Users vs JSM Force HTTP to HTTPS / SSL – No Setup, Fast and Reliable