Creative Market - Buy and sell handcrafted, mousemade design content like vector patterns, icons, photoshop brushes, fonts and more at Creative Market.
SocialSizes - Sketch templates for sharing images & videos on social media
Pixelify - A new way to download and share free design assets
UI/UX Assets - Curated UI kits, wireframes, templates, icons and more.
UI8 - Carefully crafted UI design assets
Headers.me - Create social cover images that get you followers