CSS

.slideanim {visibility:hidden;}
.slide {
    /* The name of the animation */
    animation-name: slide;
    -webkit-animation-name: slide; 
    /* The duration of the animation */
    animation-duration: 1s; 
    -webkit-animation-duration: 1s;
    /* Make the element visible */
    visibility: visible; 
}

/* Go from 0% to 100% opacity (see-through) and specify the percentage from when to slide in the element along the Y-axis */
@keyframes slide {
    0% {
        opacity: 0;
        -webkit-transform: translateY(70%);
    } 
    100% {
        opacity: 1;
        -webkit-transform: translateY(0%);
    } 
}
@-webkit-keyframes slide {
    0% {
        opacity: 0;
        -webkit-transform: translateY(70%);
    } 
    100% {
        opacity: 1;
        -webkit-transform: translateY(0%);
    }
}

jQuery

$(window).scroll(function() {
  $(".slideanim").each(function(){
    var pos = $(this).offset().top;

    var winTop = $(window).scrollTop();
    if (pos < winTop + 600) {
      $(this).addClass("slide");
    }
  });
});

Reference: Bootstrap Theme “Company”