The Summer Creative Design Bundle has tons of UI/US design resources. It includes over 700 megabytes of professional-quality PSD files, hundreds of icons optimized for both web and mobile, lots of high resolution textures, print templates, and text styles, and so much more. As a designer, this bundle will have you set to create any design you can dream up.
Normally all of the resources in this bundle would cost you $658, but for a limited time you can get them for only $39. You can grab the Summer Creative Design Bundle here.