Monsters for Sketch - Create your own monster character in seconds.
Base UI Sketch Framework - Huge set of everything you need to design and prototype
Sketch 42 - Now with export presets, touch bar integration, and more
SketchCasts - A weekly screencast, all about how to use Sketch
Now UI Kit - A beautiful Bootstrap 4 UI kit. Yours free.
Remake - A way to make web apps with just HTML & CSS