responsivelyLazy is a nice lazy loading implementation that is responsive, truly lazy and SEO friendly.
lazysizes is a fast lazyloader for images (including responsive images), iframes and scripts/widgets without any dependency. It may become also your number one tool to integrate responsive images.
BttrLazyLoading is a jQuery plugin that allows your web application to defer image loading until images are scrolled to but not only! BttrLazyLoading also allows you to have different version of an image for 4 differents screen sizes: phones (<768px), tablets (≥768px), desktops (≥992px) and large Desktops (≥1200px).
Responsive lazy loader allows you lo load the most appropriate image renditions according to the current breakpoint and to the current display into the CSS grid-system.