Sketch Talk - A community for Sketch users of all skill levels
App Store Template - A quick App Store template for Sketch with Presets
SketchCasts - A weekly screencast, all about how to use Sketch
Sketch to App Store - Generate App Store images for all iPhone sizes from Sketch
Sketch 101 by Designlab - Learn Sketch in this free course w/ downloadable templates
Timeline for Sketch - Create beautiful timeline animations in Sketch