Industry standards are only just beginning to develop for UI design software. Most programs can deliver similar results as others, but the differentiating factor is the speed and consistency that they can produce. 
The industry standard for UI design. It is unfortunately not available on PC.  It's a vector based design program that has a wide range of features that you can read more about here
Adobe XD
Adobe's answer to sketch. It is also a vector based design program that offers a feature set very similar to sketch. The benefit is that it comes with Adobe CC and it's on both mac and PC. Read more here