Eye-Tracking Options

Some links for various eye-tracking options:

Tobii (hardware, variety of markets including gaming, well-established)

iMotions (hardware, higher-end research, well-established)

Hawkeye (iOS using TrueDepth camera, limited to latest iOS devices)

Skyle for iPad (hardware, new in 2020)

EyeZag (camera-based, no longer accepting new customers)

WebGazer.js (camera-based, browser, open source)

SeeSo (mobile eye-tracking)

Useful:

10 Most Used Eye Tracking Metrics and Terms

And a summary related to mobile games:

TrackMaze: A Comparison of Head-tracking, Eye-tracking, and Tilt as Input Methods for Mobile Games

"Mobile eye-tracking has progressed in recent years but compared to desktop eye-tracking, 'it is still in its infancy'"