Usability Testing Exchange - Free usability testing of, and feedback about, your website/app.
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!
UserTest.io - User testing made simple. High-quality, affordable user testing solutions from real users, here in the UK. Improve your usability!
Userbrain - You want to improve the usability of your website? See how real people use your website for the first time, find out what works, and what needs to be improved.
userinput.io - Get on-demand feedback for your app, website or idea. Learn how to improve by hearing real opinions.
UsabilityTools - Where UX meets Conversion. Unlock the Potential Behind Remote Research and Testing