HackerOne - HackerOne provides a platform designed to streamline vulnerability coordination and bug bounty program by enlisting hackers.
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!
YesWeHack - Global Bug Bounty & Vulnerability Management Platform
Userbrain - Easy, fast, and affordable user testing for websites and prototypes.
Bugcrowd - Harness the largest pool of curated and ranked security researchers to run the most efficient bug bounty and penetration tests
userinput.io - Get on-demand feedback for your app, website or idea. Learn how to improve by hearing real opinions.