Platforma - Wireframe library of layouts and UI elements
MontageJS - MontageJS framework is a platform to develop and create single page applications (which load single HTML page and dynamically update the app as the user puts in inputs or requests or interacts with the page.) with ease.
Contra Wireframe Kit - Open source wireframe kit for design and prototyping 🚀
Vireflow - A responsive wireframe kit for Webflow
Source Wireframe Kit - Library of 537 blocks for desktop and mobile prototyping
Apple Watch UI Kit - Quickly create Apple Watch app prototypes