Lazy Sizes
lazySizes is the ultimate and lightweight lazyLoader which lazy loads images (including responsive images (picture/srcset)), iframes and scripts. It is written in VanillaJS and with high performance in mind.
Related Resources
Retina.js
The JavaScript helper script automatically replaces images on your page with high-resolution variants (if they exist). To use it, download the script and include it at the bottom of your page.
Flexslider
FlexSlider was built to serve up the best responsive jQuery slider around.
ImageOptim
ImageOptim removes bloated metadata, saves disk space & bandwidth by compressing images without losing quality. Available both as a Mac app and Web Service API.