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.
MockMagic - A free, easy-to-use device mockup generator
Platforma for iOS - The ultimate wireframe kit for app prototyping
Platforma - Wireframe library of layouts and UI elements
Smart Watch UI Kit - Helps smartwatch designers to design easily, 52 design
Contra Wireframe Kit - Open source wireframe kit for design and prototyping 🚀