google.maps.event.addListener(marker, 'click', function(innerMarker, innerItem) {
      return function() {
          //infowindows[innerKey].open(map, markers[innerKey]);
          //Info window of this marker
          var infowindow = new google.maps.InfoWindow({
            content: '<div class="info_wrapper"><img src="' + get_icon(innerItem.appicon) + '" class="app_icon"/>' + 
              '<span class="info_title"><strong>' + innerItem.title + '</strong></span>' + 
              '<span class="info_desc">' + innerItem.description + '</span>' + 
              '</div>', 
            maxWidth: 200
          });

          infowindow.open(map,innerMarker);
      }
    }(marker, item));

Reference:

• http://stackoverflow.com/questions/7044587/adding-multiple-markers-with-infowindows-google-maps-api