http://bohemiancoding.com/sketch/

Work better, faster.
Sketch is built for modern graphic designers, and it shows in every fibre of the app. From a flexible workflow with support for Multiple Pages and Artboards. Powerful features like Symbols and Shared Styles are there to make reusing elements quick and easy.

Produce better results.
Easily create complex shapes with our state-of-the-art vector boolean operations and take advantage of our extensive layer styles. Sketch’s fully vector-based workflow makes it easy to create beautiful, high-quality artwork from start to finish