Theme Forest - The #1 marketplace for premium website templates, including themes for WordPress, Magento, Drupal, Joomla, and more. Create a website, fast.
Anthony Boyd Graphics - Anthony Boyd Graphics is the fastest-growing platform that offers high-quality and advanced level mockups, textures, 3D models, and UI kits for free to help designers to save time and effort.
UpLabs - The best material design, iOS & web resources, every day
Mockups Design - Mockups Design is the most leading web-based application that comes with a vast collection of creatively design mockups for all kinds of products and devices.
UI8 - Carefully crafted UI design assets
Mockuuups Studio - Fast and easy way to create product mockups on macOS, Windows and Linux.