Sally Blocks is a huge free set of ready to use elements and components for simple and fast creating of responsive web pages. With it's help you can construct any kind of landing page.
Free UI Kits and PSD Templates
Here you will find all the necessary assets for UI designers: website and mobile app flowcharts, wireframes, free UI kits for mobile apps and websites, ready-to-use website templates. Each UI kit is presented in PSD format, for some of them, the Sketch version is available.
Lucky Store is a huge e-commerce UI pack for designers and web developers. It contains hundreds of beautiful and clear elements which can help you to build any e-commerce project.
Numbers is a flat UI design kit all about charts, graphs and numbers. It can be very useful for creating modern web or tablet app design. Layered PSD file is included.