Except for a bug in the WIFI option that keeps alerting me that i've left my iPhone behind while I am at home, on WIFI, but at the other end of the house. Worked with Phone Buddy people, tested beta builds but could not get it to work. Could be due to mesh WIFI in my house and their app can't cross to a different AP? Who knows. I uninstalled it.
On the other hand, Apple's "left behind" doesn't seem to work at all. I turned this on a month ago and my AW never notifies me when I walk away from my house (and "home" is NOT set as an exception). I don't think it's ever notified me. If it has, it's pretty lame then as the "alert" was too quiet to be noticed, thereby being worthless.
On thing I liked about Phone Buddy was the alarm was a real alarm sound (Siren). It gets your attention. Apple's LEFT BEHIND notification is yet another "ding" notification that I already get too many of every day. Brilliant, Apple...