XT Adaptive Images is the best extension to generate responsive images. It packs Adaptive Images + HTML's new responsive image attributes (srcset and sizes) + Lazy Load + CDN in a single plugin.
A video gallery can be the best way to expose information to your visitors. In this extension, you will be able to do this in a simple and stylish way.
A responsive Joomla! slideshow with multiple image and caption layouts, CSS3 effects, video support, 24 slides per module and optional HikaShop compatiblity.