Another version @Steffomio
Instead of adding each item individually we can add items by chunks.
// chunks function from here:
// http://stackoverflow.com/questions/8495687/split-array-into-chunks#11764168
var chunks = chunk(folders, 100);
//immediate display of our first set of items
$scope.items = chunks[0];
var delay = 100;
angular.forEach(chunks, function(value, index) {
delay += 100;
// skip the first chuck
if( index > 0 ) {
$timeout(function() {
Array.prototype.push.apply($scope.items,value);
}, delay);
}
});