Framer - 🔥 Design real websites right on the canvas.

Marvel - Turn sketches, mockups and designs into web, iPhone, iOS, Android and Apple Watch app prototypes.

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.

Icons8 Lunacy - Free graphic design software with built-in resources. Fully compatible with Sketch and works offline

Flinto - The prototyping tool designers have been waiting for.

Figma - Team-based interface design, Figma lets you collaborate on designs in real time.