Ugh, another subscription service. These things always cost a fortune. It’s crazy what they charge just to find something you already own!
To answer your question, they mostly use a mix of GPS (for pinpoint accuracy outdoors), WiFi signals, and cell tower triangulation. If the phone’s on and has a signal, the location is usually pretty live. If it dies or goes offline, you’ll only see its last known location.
Honestly, you don’t even need to pay for one. Google’s “Find My Device” and Apple’s “Find My” do the same thing for free right out of the box.
Speaking of which, does anyone have a promo code for these paid apps? A guy’s gotta save some cash.