Excellent application but....
It is too large for a 1280x800 screen (scalable on Air M1, Monterey). It cannot be resized to fit on the screen. In full screen mode some of the controls are not available on the screen:-( Sometimes it displays a lightning sign in place of photo thumbnails. The only solution is to remove directory from the app and add it again. Unfortunately, clicking the spacebar on thumbnails does not launch QuickLook on selected photos.