I use it for theatrical performances on Zoom so I am interested in the zoom (digital magnify and crop) feature as well as brightness (so I can adjust the brighness of my face to naturally blend with the brightness of my virtual background.) I tried the app with other video apps, and with other camera inputs (external webcam, iPhone camera as input to computer, etc.) and found it works well, but best is with my Mac's built-in camera. So no funny faces or hats, just good control over contrast, brightness, gamma, hues, and tints etc.
This app works very well and is for people who want to look good when talking to othrs by their webcam.