WP Rocket - WP Rocket offers a caching plugin for Wordpress.
Screencastify - Free screen recorder extension for Chrome. Capture, edit and share screencasts. No software download required. Works on Mac, Windows and Chromebooks. Screen RecorderFree screen recorder for Chrome.
Autoptimize - Autoptimize makes optimizing your site really easy.
Loom - Loom is a screen recording extension for Chrome that gives people the ability to create and share media. Create your own videos using your camera, screen view, and audio. Read more about Loom.
WP Super Cache - A very fast caching system for WordPress that produces static HTML files.
SketchCasts - A weekly screencast, all about how to use Sketch