WOW.js - Animate elements on-scroll to catch attention. Such Magic.
Fancybox - fancyapps.com - Fancy App Store
Lax.js - Create beautiful & smooth animations when you scroll
PhotoSwipe - JavaScript gallery, no dependencies.
ScrollMagic - The jQuery plugin for magical scroll interactions.
Magnific Popup - The greater part of Lightbox modules will completely preload a picture before showing it.