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.

sanarena

Hit Sniffer service has shutdown on September 2016 
This plugin now serve as a memorial and soon to be deleted.
Those who look for similiar services, they can use Hit Steps.

Hit Sniffer Live Blog Analytics

Hit Sniffer was a powerful real time website visitor activity tracker.

StatCounter – Free Real Time Visitor Stats vs Hit Sniffer Live Blog Analytics