Base UI Sketch Framework - Huge set of everything you need to design and prototype
zeroqode - Build your app up to 10x faster with no-code app templates
SketchCasts - A weekly screencast, all about how to use Sketch
Flinto - The prototyping tool designers have been waiting for.
UiSketcher - Easily sketch user interface with your pen-enabled device!
Kodika.io - Build powerful iOS apps on your iPad with no code.