The download button opens the iTunes App Store, where you
may continue the download process. You must have iTunes installed with an
active iTunes account in order to download and install the software. This
download may not be available in some countries.
From Merle Ashton:
Relay Tests is the follow up to RELAYS 101. This app will give random test question values and check your answers. The protective relay simulators will require you to find the settings presently in the simulated relays and then you must install new given settings. It's as frustrating as real life!