Sketch Talk - A community for Sketch users of all skill levels
5play.ru - 5play.ru enables you to download highly-rated Apps and Games for Android devices.
SketchCasts - A weekly screencast, all about how to use Sketch
iOSGODS! - iOSGODS!
Sketch 101 by Designlab - Learn Sketch in this free course w/ downloadable templates
Altstore - A home for apps that push the boundaries on iOS