Snooper 2.0 detects hardware problems and sources of intermittent failures. It performs over 200 major component tests, prints the results, and logs errors. It also does benchmark testing and reports on system configurations to allow technicians to find and fix problems quickly.
If you have a II-series Mac, there was also a NuBus card that went with it. It could test the power supply, NuBus, serial, and ADB ports. Sort of a poor man's version of the official Apple TechStep.