Mockuuups Studio - Fast and easy way to create product mockups on macOS, Windows and Linux.
Contra Wireframe Kit - Open source wireframe kit for design and prototyping 🚀
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.
Platforma - Wireframe library of layouts and UI elements
Mr. Mockup - Mr.
Craftwork - A collection of User Interface resources made by Craftwork