GrayView is a basic grayscale image viewer (and later editor) for early Macs that was initially developed in order to display ThunderScan "SCAN" files and convert them into 32-gray shade images.
From the Read Me for v1.9.8a4:
Category:
Visual Arts & Graphics
Year released:
1988
System:
System 1 - 5
System 6.x
Emulation:
Mini vMac (68k)
Mini vMac II (68k)
Architecture:
68k