update app-download layer position dynamicly for the home page

@@ -68,7 +68,7 @@ $channelLink.on('touchstart', function() {
         borderColor: '#fff'
     });
 });
-var removeAppFloatLayerFixed = (function() {
+var updateLayerPosition = (function() {
    var init = false;
    return function() {
      var winHeight = window.innerHeight;
@@ -92,11 +92,7 @@ var removeAppFloatLayerFixed = (function() {
 })();
 
 $win.scroll(function() {
-
-  clearTimeout($.data(this, 'scrollTimer'));
-  $.data(this, 'scrollTimer', setTimeout(function() {
-      removeAppFloatLayerFixed();
-  }, 2));
+  updateLayerPosition();
 });
 
 $win.on('resize', function(){
@@ -107,4 +103,4 @@ $win.on('scrollstop', function(){
   console.log('stop');
 });
 
-$doc.on('ready', removeAppFloatLayerFixed);
+$doc.on('ready', updateLayerPosition);