Select all links with hashes, MMenu mobile plugin, click menu button and scroll down on mobile.

jQuery

		// Select all links with hashes
		$('.menu-item-1385 a, .menu-item-1386 a, .menu-item-1387 a, .menu-item-1383 a')
			.click(
				function(event) {
					// On-page links

					// console.log(this);

					if (
						location.pathname.replace(/^\//, '') == this.pathname.replace(/^\//, '')
						&&
						location.hostname == this.hostname
					) {

						// Figure out element to scroll to
						var target = $(this.hash);
						target = target.length ? target : $('[name=' + this.hash.slice(1) + ']');

						// console.log(target);

						// Does a scroll target exist?
						if (target.length) {
							// Only prevent default if animation is actually gonna happen
							event.preventDefault();
							$('html, body').animate({
								// scrollTop: target.offset().top-100
								scrollTop: target.offset().top
							}, 1000, function() {
								// Callback after animation
								// Must change focus!
								var $target = $(target);
								$target.focus();
								if ($target.is(":focus")) { // Checking if the target was focused
									return false;
								} else {
									$target.attr('tabindex','-1'); // Adding tabindex for elements not focusable
									$target.focus(); // Set focus again
								};
							});
						}
					}
				}
			);