diff --git a/css/main.css b/css/main.css
index a4b069b..8117efe 100644
--- a/css/main.css
+++ b/css/main.css
@@ -409,7 +409,7 @@ button > * {
   right: 8px;
 }
 .ol-popup-closer:after {
-  content: "✖";
+  content: "×";
 }
 
 #switcher {
diff --git a/js/src/mapapi/api_openlayers.js b/js/src/mapapi/api_openlayers.js
index 2325e26..9ae353d 100644
--- a/js/src/mapapi/api_openlayers.js
+++ b/js/src/mapapi/api_openlayers.js
@@ -253,12 +253,9 @@ export default class OpenLayersApi {
     popupContent.id = 'popup-content';
     popupContainer.appendChild(popupContent);
     const popupCloser = document.createElement('a');
-    popupCloser.id = 'popup-closer';
     popupCloser.className = 'ol-popup-closer';
-    popupCloser.href = '#';
     popupContainer.appendChild(popupCloser);
 
-
     this.popup = new ol.Overlay({
       element: popupContainer,
       autoPan: true,
@@ -347,6 +344,9 @@ export default class OpenLayersApi {
     switcherContent.id = 'switcher-content';
     switcherContent.className = 'ol-layerswitcher';
     switcher.appendChild(switcherContent);
+    const switcherCloser = document.createElement('a');
+    switcherCloser.className = 'ol-popup-closer';
+    switcher.appendChild(switcherCloser);
 
     this.map.getLayers().forEach(/** @param {Layer} _layer */(_layer) => {
       const layerLabel = document.createElement('label');
@@ -387,6 +387,7 @@ export default class OpenLayersApi {
       }
     };
 
+    switcherCloser.addEventListener('click', switcherHandle, false);
     switcherButton.addEventListener('click', switcherHandle, false);
     switcherButton.addEventListener('touchstart', switcherHandle, false);
 
diff --git a/js/src/position.js b/js/src/position.js
index 951a3f6..a52b725 100644
--- a/js/src/position.js
+++ b/js/src/position.js
@@ -83,4 +83,12 @@ export default class uPosition {
   hasImage() {
     return (this.image != null && this.image.length > 0);
   }
+
+  get calculatedSpeed() {
+    return this.seconds ? this.meters / this.seconds : 0;
+  }
+
+  get totalSpeed() {
+    return this.totalSeconds ? this.totalMeters / this.totalSeconds : 0;
+  }
 }
diff --git a/js/src/positionset.js b/js/src/positionset.js
index 736bad7..2de4b38 100644
--- a/js/src/positionset.js
+++ b/js/src/positionset.js
@@ -82,19 +82,33 @@ export default class uPositionSet extends uListItem {
 
   /**
    * Fetch latest position of each user.
-   * @return {Promise<uPositionSet, Error>}
+   * @return {Promise<void, Error>}
+   */
+  fetchLatest() {
+    this.clear();
+    return uPositionSet.fetch({ last: true }).then((_positions) => {
+      this.fromJson(_positions);
+    });
+  }
+
+  /**
+   * Fetch latest position of each user.
+   * @return {Promise<?uPositionSet, Error>}
    */
   static fetchLatest() {
-    return this.fetch({ last: true }).then((_positions) => {
-      if (_positions.length) {
-        const set = new uPositionSet();
-        set.fromJson(_positions);
+    const set = new uPositionSet();
+    return set.fetchLatest().then(() => {
+      if (set.length) {
         return set;
       }
       return null;
     });
   }
 
+  /**
+   * @param params
+   * @return {Promise<Object[], Error>}
+   */
   static fetch(params) {
     return uAjax.get('utils/getpositions.php', params);
   }
diff --git a/js/src/user.js b/js/src/user.js
index d4cef04..4459837 100644
--- a/js/src/user.js
+++ b/js/src/user.js
@@ -43,7 +43,7 @@ export default class uUser extends uListItem {
   }
 
   /**
-   * @return {Promise<uTrack, string>}
+   * @return {Promise<uTrack, Error>}
    */
   fetchLastPosition() {
     return uTrack.fetchLatest(this);
@@ -51,7 +51,7 @@ export default class uUser extends uListItem {
 
   /**
    * @throws
-   * @return {Promise<uUser[], string>}
+   * @return {Promise<uUser[], Error>}
    */
   static fetchList() {
     return uAjax.get('utils/getusers.php').then((_users) => {
diff --git a/js/src/utils.js b/js/src/utils.js
index e79c8ef..f362b9b 100644
--- a/js/src/utils.js
+++ b/js/src/utils.js
@@ -294,24 +294,13 @@ export default class uUtils {
   static openUrl(url) {
     window.location.assign(url);
   }
+
+  /**
+   * @param {Error} e
+   * @param {string} message
+   */
+  static error(e, message) {
+    console.error(`${e.name}: ${e.message} (${e.stack})`);
+    alert(message);
+  }
 }
-
-// seconds to (d) H:M:S
-Number.prototype.toHMS = function () {
-  let s = this;
-  const d = Math.floor(s / 86400);
-  const h = Math.floor((s % 86400) / 3600);
-  const m = Math.floor(((s % 86400) % 3600) / 60);
-  s = ((s % 86400) % 3600) % 60;
-  return ((d > 0) ? (d + ' d ') : '') + (('00' + h).slice(-2)) + ':' + (('00' + m).slice(-2)) + ':' + (('00' + s).slice(-2)) + '';
-};
-
-// meters to km
-Number.prototype.toKm = function () {
-  return Math.round(this / 10) / 100;
-};
-
-// m/s to km/h
-Number.prototype.toKmH = function () {
-  return Math.round(this * 3600 / 10) / 100;
-};
diff --git a/js/test/track.test.js b/js/test/track.test.js
index 8d2aea8..a0183e8 100644
--- a/js/test/track.test.js
+++ b/js/test/track.test.js
@@ -70,22 +70,22 @@ describe('Track tests', () => {
     seconds = 0;
 
     jsonPosition = {
-      'id': posId,
-      'latitude': latitude,
-      'longitude': longitude,
-      'altitude': altitude,
-      'speed': speed,
-      'bearing': bearing,
-      'timestamp': timestamp,
-      'accuracy': accuracy,
-      'provider': provider,
-      'comment': comment,
-      'image': image,
-      'username': username,
-      'trackid': trackid,
-      'trackname': trackname,
-      'meters': meters,
-      'seconds': seconds
+      id: posId,
+      latitude: latitude,
+      longitude: longitude,
+      altitude: altitude,
+      speed: speed,
+      bearing: bearing,
+      timestamp: timestamp,
+      accuracy: accuracy,
+      provider: provider,
+      comment: comment,
+      image: image,
+      username: username,
+      trackid: trackid,
+      trackname: trackname,
+      meters: meters,
+      seconds: seconds
     };
   });
 
diff --git a/scripts/import_cli.php b/scripts/import_cli.php
index 30ff49d..215a790 100644
--- a/scripts/import_cli.php
+++ b/scripts/import_cli.php
@@ -158,7 +158,7 @@ foreach ($gpxFiles as $i => $gpxFile) {
         $provider = "gps";
         if (!empty($point->extensions)) {
           // parse ulogger extensions
-          $ext = $point->extensions->children('ulogger', TRUE);
+          $ext = $point->extensions->children('ulogger', true);
           if (count($ext->speed)) { $speed = (double) $ext->speed; }
           if (count($ext->bearing)) { $bearing = (double) $ext->bearing; }
           if (count($ext->accuracy)) { $accuracy = (int) $ext->accuracy; }