Vast HTML

This will allow you to display exacly how many users total are on your blog.
For more information on the plugin visit: http://vasthtml.com/js/total-users-plugin/

Total Users

shows how many user are on your Wordpress blog.

TrustedLogin

The easiest and safest way to restrict access to your WordPress site’s Dashboard and administrative menus. Remove Dashboard Access is a lightweight plugin that automatically redirects users who shouldn’t have access to the Dashboard to a custom URL of your choosing. Redirects can also be configured on a per-role/per-capability basis, allowing you to keep certain users out of the Dashboard, while retaining access for others.
<ul>
<li>Limit Dashboard access to user roles:
<ul>
<li>Admins only</li>
<li>Admins + editors</li>
<li>Admins, editors, and authors</li>
<li>or restrict by specific user capability</li>
</ul>
</li>
<li>Choose your own redirect URL</li>
<li>Optionally allow users to edit their profiles</li>
<li>Display a message on the login screen so users know why they’re being redirected</li>
<li>Allow specific admin pages through the redirect — paste a list of URLs your customers should still be able to reach (with wildcard support for grouping related pages)</li>
<li>Optionally extend the block to <code>admin-ajax.php</code> requests for stricter lockdown</li>
</ul>
Blocking access to the Dashboard is a great way to prevent clients from breaking their sites, prevent users from seeing things they shouldn’t, and to keep your site’s backend more secure.
Allow only users with roles or capabilities:
You can restrict Dashboard access to Admins only, Editors or above, Authors or above, or by selecting a specific user capability.
Grant access to user profiles:
Optionally allow all users the ability to edit their profiles in the Dashboard. Users lacking the chosen capability won’t be able to access any other sections of the Dashboard.
Show a custom login message:
<ul>
<li>Supply a message to display on the login screen. Leaving this blank disables the message.</li>
</ul>
Allow specific admin pages through the redirect:
Sometimes you want to lock down the Dashboard but still let your customers reach one or two specific admin pages — a payment confirmation, a <a href="https://www.trustedlogin.com/" rel="nofollow ugc">TrustedLogin</a> secret-share screen, a custom report. Paste those URLs into the Allowed URLs box (one per line, relative or absolute), and matching requests will skip the redirect.
Use <code>*</code> as a wildcard inside a query value to match a whole group of pages at once. For example, <code>?page=tl-*</code> allows <code>tl-secrets</code>, <code>tl-config</code>, and any other page whose slug starts with <code>tl-</code>.
Optionally block AJAX requests too:
By default this plugin doesn’t touch requests to <code>admin-ajax.php</code> — most WordPress sites rely on those for legitimate frontend AJAX. If you’d rather the dashboard restriction apply there as well, turn on the “Also block AJAX” checkbox in the Advanced section of the settings page.

Remove Dashboard Access

This plugin is a must-have when working with public roles.

A must-have!

Disable Dashboard access for users of a specific role or capability. Disallowed users are redirected to a chosen URL. Get set up in seconds.

Total Users vs Remove Dashboard Access