Framer - 🔥 Design real websites right on the canvas.

UserTesting.com - Usability testing has never been easier. Get videos of real people speaking their thoughts as they use websites, mobile apps, prototypes and more!

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.

Userbrain - Easy, fast, and affordable user testing for websites and prototypes.

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

userinput.io - Get on-demand feedback for your app, website or idea. Learn how to improve by hearing real opinions.