Creative Market - Buy and sell handcrafted, mousemade design content like vector patterns, icons, photoshop brushes, fonts and more at Creative Market.
IconStore - Free icon packs by first-class designers
SocialSizes - Sketch templates for sharing images & videos on social media
Feather Icons - Simply beautiful open source icons
Designify - Turn any photo into awesome, automatically
Streamline icons - The world’s largest icon pack library - 100k icons and illustrations.