<input type="file" id="0" name="photos[]" multiple hidden required class="photos">

$('form').submit(function () {
    $('input.photos').val(photos);
}

var ids = [0];
var photoNames = [];
var append = false;

$('span#photo-uploader').click(function (e) {
    $('input.photos#' + ids[ids.length - 1]).click();
});

$('body').on('change', 'input.photos', function () {

    var input = this;
    var photoList = $('div.photo-list');

    for (var i = 0; i < input.files.length; i++) {
        var file = input.files[i];

        if (photoNames.indexOf(file.name) !== -1) continue;

        append = true;

        photoNames.push(file.name);

        var reader = new FileReader();

        reader.onloadstart = (function (file, i) {
            return function (e) {
                photoList.append(photoItem(e, file, i));
            }
        }) (file, i + photoNames.length);

        reader.onload = (function (i) {
            return function (e) {
                $('div#' + i + '.photo-item img').attr('src', e.target.result);
            }
        }) (i + photoNames.length);

        reader.onprogress = function (e) {
            if (e.lengthComputable) {
                var progress = Math.round(e.loaded / e.total * 100);
                $('div#' + i + '.photo-item div.progress-bar').css('width', progress + '%');
            }
        };

        reader.readAsDataURL(file);
    }

    if (append) {
        $('div.kek').append('<input type="file" id="' + (ids[ids.length - 1] + 1) + '" name="photos[]" multiple class="photos">');
        ids.push(ids[ids.length - 1] + 1);
        append = false;
    }

});

function photoItem(e, file, i) {

    return ''; // рендерит фотку
}