Fore those not familiar with the Apple ecosystem, what does "Find My" do? locate apple devices ?
Correct. You can also share your location with friends. A lot of friend groups (at least my age) use Find My as a kind of social network.
How does that work woth your friends? Always on access or just occasionally?
Always on. You can see where your friends are at both in Find My and under their contact photo in your iMessages chat.
Personally I do not find the idea comforting that someone (anyone) may know where I am at all times. I would not even trust Apple either.