I started to put this in General, but I don't know what the lightning rules/guidelines are in Fed rules. Even if your assertion is correct, the key word you said was "most," not all. I've been to DIII schools that were less sophisticated than even moderate sized high schools I've worked. Plus, there are many officials on here that work Texas (and probably Mass.) high schools that not only don't have lightning meters (or, as you worded, sophisticated equipment), but know little if anything about lightning guidelines in general.
OBVIOUSLY, if you have better equipment at your disposal, it would be idiotic to not use it. But my post assumed you didn't -- perhaps I should have made that more clear. Or, ignore the app completely. It was strictly information I thought some might be interested in.