Worbee Ltd

This plugin collects actions performed by existing WordPress users and shows that data in an easy-to-process table.
The plugin won’t track guests (non-logged visitors) of your website. 
It does not create any additional cookies. You may want to inform your registered users that some of their actions are being stored. This includes any type of visitors that have an account within your WordPress installation. 
No user information is being sent outside of your installation.
The statistics are available to Administrators only by default.
Use cases:
<ul>
<li>check if your users have logged in recently</li>
<li>check who is most active</li>
<li>verify that your editors and authors are editing content</li>
<li>monitor which content is being worked on</li>
</ul>
<h3>Simple:</h3>
<ol>
<li>Login to your WordPress dashboard.</li>
<li>Navigate to Plugins -> Add new</li>
<li>Search for <code>User Stats WP</code></li>
<li>Install</li>
<li>Activate</li>
</ol>

User stats WP

Stores and displays user generated events, like logins and post edits.

StatCounter

The Official StatCounter WordPress Plugin brings you all the powerful StatCounter features to your wordpress blog.
Including but not limited to the following:
<ul>
<li><a href="http://statcounter.com/features/#invisible-counter" rel="nofollow ugc">Invisible Counter Option</a></li>
<li><a href="http://statcounter.com/features/#configurable-counter" rel="nofollow ugc">Configurable Counter</a></li>
<li><a href="http://statcounter.com/features/#configurable-summary-stats" rel="nofollow ugc">Configurable Summary Stats</a></li>
<li><a href="http://statcounter.com/features/#magnify-user" rel="nofollow ugc">Magnify User</a></li>
<li><a href="http://statcounter.com/features/#drill-down" rel="nofollow ugc">Drill Down</a></li>
<li><a href="http://statcounter.com/features/#popular-pages" rel="nofollow ugc">Popular Pages</a></li>
<li><a href="http://statcounter.com/features/#entry-pages" rel="nofollow ugc">Entry Pages</a></li>
<li><a href="http://statcounter.com/features/#exit-pages" rel="nofollow ugc">Exit Pages</a></li>
<li><a href="http://statcounter.com/features/#came-from" rel="nofollow ugc">Came From</a></li>
<li><a href="http://statcounter.com/features/#keyword-analysis" rel="nofollow ugc">Keyword Analysis</a></li>
<li><a href="http://statcounter.com/features/#recent-keyword-activity" rel="nofollow ugc">Recent Keyword Activity</a></li>
<li><a href="http://statcounter.com/features/#search-engine-wars" rel="nofollow ugc">Search Engine Wars</a></li>
<li><a href="http://statcounter.com/features/#visitor-paths" rel="nofollow ugc">Visitor Paths</a></li>
<li><a href="http://statcounter.com/features/#visit-length" rel="nofollow ugc">Visit Length</a></li>
<li><a href="http://statcounter.com/features/#returning-visits" rel="nofollow ugc">Returning Visits</a></li>
<li><a href="http://statcounter.com/features/#recent-pageload-activity" rel="nofollow ugc">Recent Pageload Activity</a></li>
<li><a href="http://statcounter.com/features/#recent-visitor-activity" rel="nofollow ugc">Recent Visitor Activity</a></li>
<li><a href="http://statcounter.com/features/#country-state-city-stats" rel="nofollow ugc">Country/State/City Stats</a></li>
<li><a href="http://statcounter.com/features/#visitor-map" rel="nofollow ugc">Recent Visitor Google Map</a></li>
<li><a href="http://statcounter.com/features/#isp-stats" rel="nofollow ugc">ISP Stats</a></li>
<li><a href="http://statcounter.com/features/#browser-stats" rel="nofollow ugc">Browser Stats</a></li>
<li><a href="http://statcounter.com/features/#os-stats" rel="nofollow ugc">O.S. Stats</a></li>
<li><a href="http://statcounter.com/features/#resolution-stats" rel="nofollow ugc">Resolution Stats</a></li>
<li><a href="http://statcounter.com/features/#javascript-stats" rel="nofollow ugc">JavaScript Stats</a></li>
<li><a href="http://statcounter.com/features/#email-reports" rel="nofollow ugc">Email Reports</a></li>
<li><a href="http://statcounter.com/features/#multiple-site-management" rel="nofollow ugc">Multiple Site Management</a></li>
<li><a href="http://statcounter.com/features/#user-access-management" rel="nofollow ugc">User Access Management</a></li>
<li><a href="http://statcounter.com/features/#public-stats" rel="nofollow ugc">Public Stats</a></li>
<li><a href="http://statcounter.com/features/#blocking-cookie" rel="nofollow ugc">Blocking Cookie</a></li>
</ul>

StatCounter – Free Real Time Visitor Stats

StatCounter.com powered real-time detailed stats about the visitors to your blog.

User stats WP vs StatCounter – Free Real Time Visitor Stats