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!

TrackIR - TrackIR adds depth to the PC gaming experience by enabling players to take control of the in-game view.

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

FaceTrackNoIR - FaceTrackNoIR is only available for Windows-based PC's (sorry, we have to start somewhere) and...

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

GiMeSpace Cam Control - Control your computer by making gestures in front of the webcam.