diff --git a/README b/README
index 256d018..d883843 100755
--- a/README
+++ b/README
@@ -2,7 +2,8 @@ This is a simple web viewer for GPS tracks uploaded with mobile client.
 It is designed to work with Android version of great app TrackMe (http://www.luisespinosa.com/trackme_eng.html), 
 but it should be easy to adjust it for other clients (other database tables).
 Interface "look and feel" is based on TrackMe Display (http://forum.xda-developers.com/showthread.php?t=477394).
-It is possible to switch between Google Maps API and OpenLayers API with OpenStreetMap (any other compatible base layer).
+It is possible to switch between Google Maps API and OpenLayers API with OpenStreetMap (or any other compatible base layer).
+It also supports Backitude client (thanks to markcs: see README_Backitude).
 
 Live demo:
 - http://flaa.fabiszewski.net/phptrackme/
diff --git a/auth.php b/auth.php
index c3978ef..96a12c3 100755
--- a/auth.php
+++ b/auth.php
@@ -31,6 +31,7 @@ if ($mysqli->connect_errno) {
 }
 $mysqli->set_charset("utf8");
 $auth = NULL;
+$admin = NULL;
 if ($require_authentication) {
   /* authentication */
   session_name('trackme');
@@ -38,6 +39,7 @@ if ($require_authentication) {
   $sid = session_id();
   
   $auth = (isset($_SESSION['auth']) ? $_SESSION['auth'] : "");
+  $admin = (isset($_SESSION['admin']) ? $_SESSION['admin'] : "");
   $user = (isset($_REQUEST['user']) ? $_REQUEST['user'] : "");
   $pass = (isset($_REQUEST['pass']) ? md5($salt.$_REQUEST['pass']) : "");
   $ssl = ((!isset($_SERVER['HTTPS']) || $_SERVER['HTTPS'] == "" || $_SERVER['HTTPS'] == "off") ? "http" : "https");
@@ -98,12 +100,10 @@ if ($require_authentication) {
       // start new session
       session_name('trackme');    
       session_start();
-      if (($user==$admin_user) and ($admin_user != "")) {
-          $_SESSION['auth'] = $admin_user;
-      }
-      else {
-          $_SESSION['auth'] = $rec_ID;
+      if (($user==$admin_user) && ($admin_user != "")) {
+          $_SESSION['admin'] = $admin_user;
       }
+      $_SESSION['auth'] = $rec_ID;
       $url = str_replace("//", "/", $_SERVER['HTTP_HOST'].dirname($_SERVER['SCRIPT_NAME'])."/index.php");
       header("Location: $ssl://$url");
       exit;    
diff --git a/config.php b/config.php
index 534dd3b..4aa40c2 100755
--- a/config.php
+++ b/config.php
@@ -17,7 +17,7 @@
  * License along with this program; if not, write to the Free Software
  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
-$version = "2.2"; 
+$version = "2.3"; 
 
 // default map drawing framework 
 // (gmaps = google maps, openlayers = openlayers/osm)
diff --git a/index.php b/index.php
index 71ba1d2..ad91269 100755
--- a/index.php
+++ b/index.php
@@ -20,7 +20,7 @@
 require_once("config.php");
 require_once("auth.php");
 
-if (($auth) and ($auth != $admin_user)) {
+if ($auth && !$admin) {
   // get username
   $query = "SELECT username FROM users WHERE ID='$auth' LIMIT 1"; 
   $result = $mysqli->query($query);
@@ -33,25 +33,37 @@ if (($auth) and ($auth != $admin_user)) {
 else {
   // free access or admin user
   // prepare user select form
-  if (($auth == $admin_user) and ($admin_user != "")) {
-     $user = $auth;
-     $auth = NULL;
+  if ($admin) {
+     $user = $admin_user;
   }
   $user_form = '
-  <u>'.$lang_user.'</u><br />
+  <u>'.$lang_user.'</u> ';
+  if ($auth) {
+    $user_form .= '&nbsp;'.$user.' (<a href="logout.php">'.$lang_logout.'</a>)';
+  }  
+  $user_form .= '
+  <br />
   <form>
   <select name="user" onchange="selectUser(this)">
   <option value="0">'.$lang_suser.'</option>';  
+  // get last position user
+  $query = "SELECT FK_Users_ID FROM positions ORDER BY DateOccurred LIMIT 1";
+  $result = $mysqli->query($query);
+  if ($result->num_rows) {
+    $last = $result->fetch_row();
+    $last_id = $last[0];
+  } else {
+    $last_id = "";
+  }
   $query = "SELECT ID,username FROM users ORDER BY username"; 
   $result = $mysqli->query($query);
   while ($row = $result->fetch_assoc()) {
-    $user_form .= sprintf("<option value=\"%s\">%s</option>\n", $row["ID"], $row["username"]);    
+    $user_form .= sprintf("<option %svalue=\"%s\">%s</option>\n", ($row["ID"] == $last_id)?"selected ":"",$row["ID"], $row["username"]);    
   }
-$user_form .= '
-</select>
-</form>
-';
-  $user_form .= '<u>'.$lang_user.'</u><br />'.$user.' (<a href="logout.php">'.$lang_logout.'</a>)';
+  $user_form .= '
+  </select>
+  </form>
+  ';
 }
 
 // prepare track select form
@@ -59,7 +71,15 @@ $track_form = '
 <u>'.$lang_track.'</u><br />
 <form>
 <select name="track" onchange="selectTrack(this)">';
-$query = "SELECT * FROM trips WHERE FK_Users_ID='$auth' ORDER BY ID DESC"; 
+$userid = "";
+if ($auth && !$admin) {
+  // display track of authenticated user
+  $userid = $auth;
+} elseif ($last_id) {
+  // or user who did last move
+  $userid = $last_id;
+}
+$query = "SELECT * FROM trips WHERE FK_Users_ID='$userid' ORDER BY ID DESC"; 
 $result = $mysqli->query($query);
 
 $trackid = "";
@@ -115,7 +135,7 @@ print
     <link rel="stylesheet" type="text/css" href="main.css" />
     <script>
       var interval = '.$interval.';
-      var userid = '.(($auth)?$auth:-1).';
+      var userid = '.(($userid)?$userid:-1).';
       var trackid = '.(($trackid)?$trackid:-1).';
       var lang_user = "'.$lang_user.'";
       var lang_time = "'.$lang_time.'";
diff --git a/main.js b/main.js
index 7d18bb1..4692ea1 100755
--- a/main.js
+++ b/main.js
@@ -243,9 +243,13 @@ function getTrips(userid) {
   xhr.onreadystatechange = function() {
     if (xhr.readyState==4 && xhr.status==200) {
       var xml = xhr.responseXML;
+      var trackSelect =  document.getElementsByName('track')[0];
+      clearOptions(trackSelect);
       var trips = xml.getElementsByTagName('trip');
       if (trips.length>0) {  
         fillOptions(xml);
+      } else {
+        clearMap();
       }
       xhr = null;
     }
@@ -256,7 +260,6 @@ function getTrips(userid) {
 
 function fillOptions(xml) {
   var trackSelect =  document.getElementsByName('track')[0];
-  clearOptions(trackSelect);
   var trips = xml.getElementsByTagName('trip');
   var trpLen = trips.length;
   for (var i=0; i<trpLen; i++) {