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!

Mio - Powering seamless communication between workplace chat apps.

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

Slackin - Create your own public Slack chat community

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

Chats.Directory - A curated list of the best Slack groups for professionals