diff --git a/img/default-icon.svg b/img/default-icon.svg
new file mode 100644
index 0000000..142398b
--- /dev/null
+++ b/img/default-icon.svg
@@ -0,0 +1 @@
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 512 512" ><path d="M0 0h512v512H0z" fill="transparent" stroke="#fff" stroke-width="0"></path><path d="M256 16C123.45 16 16 123.45 16 256s107.45 240 240 240 240-107.45 240-240S388.55 16 256 16zm0 60c99.41 0 180 80.59 180 180s-80.59 180-180 180S76 355.41 76 256 156.59 76 256 76zm-80.625 60c-.97-.005-2.006.112-3.063.313v-.032c-18.297 3.436-45.264 34.743-33.375 46.626l73.157 73.125-73.156 73.126c-14.63 14.625 29.275 58.534 43.906 43.906L256 299.906l73.156 73.156c14.63 14.628 58.537-29.28 43.906-43.906l-73.156-73.125 73.156-73.124c14.63-14.625-29.275-58.5-43.906-43.875L256 212.157l-73.156-73.125c-2.06-2.046-4.56-3.015-7.47-3.03z" fill="#fff"></path></svg>
diff --git a/js/components/desktop-app-item.jsx b/js/components/desktop-app-item.jsx
index afb4b09..f58cda6 100644
--- a/js/components/desktop-app-item.jsx
+++ b/js/components/desktop-app-item.jsx
@@ -3,6 +3,7 @@ var Util = require('../util');
 var LazyLoad = require('./mixins/lazy-load');
 
 var LOADING_ICON = 'img/hourglass.svg';
+var DEFAULT_ICON = 'img/default-icon.svg';
 
 module.exports = React.createClass({
 
@@ -53,7 +54,6 @@ module.exports = React.createClass({
   _findIcon: function(iconPath, theme) {
 
     var self = this;
-    var DEFAULT_ICON = 'application-default-icon';
 
     console.log('Search icon %s:%s', iconPath, theme);
 
diff --git a/js/components/icon-theme-selector.jsx b/js/components/icon-theme-selector.jsx
index 7c8c8e4..aa2c239 100644
--- a/js/components/icon-theme-selector.jsx
+++ b/js/components/icon-theme-selector.jsx
@@ -34,6 +34,10 @@ module.exports = React.createClass({
       );
     });
 
+    options.unshift(
+      <option key="__none__"></option>
+    );
+
     return (
       <select value={selectedTheme} onChange={this.onChange}>
         {options}
diff --git a/js/components/mixins/lazy-load.js b/js/components/mixins/lazy-load.js
index dcb6075..8339721 100644
--- a/js/components/mixins/lazy-load.js
+++ b/js/components/mixins/lazy-load.js
@@ -1,5 +1,7 @@
 var React = require('react');
 
+var _listeners = [];
+
 module.exports = {
 
   isInViewport: function() {
@@ -10,35 +12,54 @@ module.exports = {
 
     var rect = el.getBoundingClientRect();
 
+    var viewportHeight = global.window.innerHeight || global.document.documentElement.clientHeight;
+    var viewportWidth = global.window.innerWidth || global.document.documentElement.clientWidth;
+
     return (
-      rect.top >= 0 &&
-      rect.left >= 0 &&
-      rect.bottom <= (global.window.innerHeight || global.document.documentElement.clientHeight) && /*or $(window).height() */
-      rect.right <= (global.window.innerWidth || global.document.documentElement.clientWidth) /*or $(window).width() */
+      rect.bottom >= 0 &&
+      rect.right >= 0 &&
+      rect.top <= viewportHeight &&
+      rect.left <= viewportWidth
     );
 
   },
 
   componentDidMount: function() {
 
-    function _onInViewport(){
+    if(typeof this.onInViewport === 'function') {
+
+      _listeners.push(this);
+
       if( this.isInViewport() ) {
         this.onInViewport();
       }
+
     }
 
-    var el = React.findDOMNode(this);
-
-    if(typeof this.onInViewport === 'function') {
-      window.document.addEventListener('scroll', debounce(_onInViewport.bind(this), 250), true);
-    }
-
-    _onInViewport.call(this);
+  },
 
+  componentWillUnmount: function() {
+    var index = _listeners.indexOf(this);
+    if(index !== -1) return _listeners.splice(index, 1);
   }
 
 };
 
+
+var computeComponentsVisibilityDebounced = debounce(computeComponentsVisibility, 250);
+
+// Start listening for changes
+window.document.addEventListener('scroll', computeComponentsVisibilityDebounced, true);
+window.addEventListener('resize', computeComponentsVisibilityDebounced);
+
+function computeComponentsVisibility() {
+  _listeners.forEach(function(listener) {
+    if( listener.isInViewport() ) {
+      listener.onInViewport();
+    }
+  });
+}
+
 function debounce(func, wait, immediate) {
   var timeout;
 	return function() {
diff --git a/js/util/cache.js b/js/util/cache.js
new file mode 100644
index 0000000..a8a2bc7
--- /dev/null
+++ b/js/util/cache.js
@@ -0,0 +1,33 @@
+
+function Cache() {
+  this._store = {};
+}
+
+Cache.prototype.get = function(key) {
+  key = this._serialize(key);
+  return key in this._store ? this._store[key] : undefined;
+};
+
+Cache.prototype.set = function(key, value) {
+  key = this._serialize(key);
+  this._store[key] = value;
+  return this;
+};
+
+Cache.prototype._serialize = function(mixedKey) {
+  var json = JSON.stringify(mixedKey);
+  return this._hash(json);
+};
+
+Cache.prototype._hash = function(str) {
+  var hash = 0, i, chr, len;
+  if (str.length === 0) return hash;
+  for (i = 0, len = str.length; i < len; i++) {
+    chr   = str.charCodeAt(i);
+    hash  = ((hash << 5) - hash) + chr;
+    hash |= 0; // Convert to 32bit integer
+  }
+  return hash;
+};
+
+module.exports = Cache;
diff --git a/js/util/index.js b/js/util/index.js
index c9a08fc..220f14b 100644
--- a/js/util/index.js
+++ b/js/util/index.js
@@ -1,2 +1,3 @@
 exports.System = require('./system');
 exports.DesktopApps = require('./desktop-apps');
+exports.Cache = require('./cache');
diff --git a/js/util/system.js b/js/util/system.js
index 8335a92..92cda9d 100644
--- a/js/util/system.js
+++ b/js/util/system.js
@@ -2,6 +2,7 @@ var fs = require('fs');
 var cp = require('child_process');
 var glob = require('glob');
 var ini = require('ini');
+var Cache = require('./cache');
 
 /**
  * Load a JSON file
@@ -52,12 +53,22 @@ exports.runApp = function(execPath) {
   });
 };
 
+var _searchCache = new Cache();
+
 exports.findFiles = function(pattern, opts) {
   return new Promise(function(resolve, reject) {
+
+    var cachedResult = _searchCache.get([pattern, opts]);
+    if( cachedResult !== undefined) {
+      return resolve(cachedResult);
+    }
+
     glob(pattern, opts, function(err, files) {
       if(err) return reject(err);
+      _searchCache.set([pattern, opts], files);
       return resolve(files);
     });
+
   });
 };