iOS Design Kit - The newest library of native iOS templates
UMLGraph - UMLGraph is a professional automated drawing tool that allows the designers the declarative specification and drawing of UML class and sequence diagram.
Fludish Sketch UI Kit - 🌱 Fluent iOS UI Kit designed for Sketch.
yEd - yEd is a free desktop application to quickly create, import, edit, and automatically arrange diagrams. It runs on Windows, Mac OS X, and Unix/Linux.
Nucleus UI - Free UI component library to create mockups in Figma quickly
UX Flow Wireframe Prototyping System - Create beautiful user flows prototypes for your next project