I'm not sure what location service it uses, but I've been using it for a week or so now. It does exactly as advertised. It turns on my wifi when I get home and turns it off when I leave. It's been a pretty pleasant suprise for a verizon app.
I thought the verizon app was gps based also have been using it for a while works well in my opinion turns on at home and work wifi turns off in between
You can set the locations in the VZW WiFi Auto On app. I've had it on my Fascinate for a while and installed it on my GS3 as soon as I got it. It works really well and shuts off my wifi when I'm out of range from my router.