Balsamiq - Balsamiq. Rapid, effective and fun wireframing software.
iOS 12 GUI - Free collection of UI components and screens of iOS 12
Moqups - The most stunning HTML5 app for creating resolution-independent SVG mockups, wireframes & interactive prototypes for your next project
Fludish Sketch UI Kit - 🌱 Fluent iOS UI Kit designed for Sketch.
Invision - Prototyping and collaboration for design teams
Landing UI Kit - Handcrafted UI components for landing pages