Anecdote related to this/caveat to you and anyone else who may use tracking apps:
In 2010 when my (now former) boyfriend and I both installed the Google Latitude app (same idea as Find a Friend app). We installed it out of curiosity (and incredulity - his brother and brother's wife had installed the program out of distrust to keep tabs on each other. They were BOTH extremely paranoid, but also both cheating!) At home, about week or so after we had installed it while staying at the Brother/Wife's place at the beach, I had forgotten it was still on my phone. We didn't live together at the time, in fact, I lived in a rural area about 40 minutes from my BF. (I didn't even know this ever happened until he sheepishly admitted it over a year later.)
One night I fell asleep early, around 10 pm, and obviously didn't respond to the messages he sent after leaving work. Out of "concern," he opened Latitude and found that my signal was moving... It was displaying that I was moving very slowly, on a back road about 5 miles away from my house. He couldn't reach me when he tried to call, (I have poor signal at my house... which he knew) and became more worried, so he convinced his best friend to leave the firehouse they were at and to go find the location where Latitude said I was. His friend thought he was nuts, but he told his friend that he was "worried that I had been kidnapped or something" because of the unusually remote road Latitude placed me on.
Long story short, they chased the signal for almost an HOUR without finding me before his friend suggested they drive by my house to see if my car was there.... Which it was. Because I was at home. Asleep in bed. When his (more technically savvy) friend found out that the signal at my house was terrible, he reasoned that it was bouncing to the nearest tower (which they had passed several times during the hour of chasing my "location") and incorrectly showing my location. D'OH.
So while I'm sure that technology has advanced and gps location has gotten more accurate, 2010 wasn't terribly long ago and GPS availability wasn't drastically different. Be careful how seriously you (or your spouse) take the information. It can lead to unnecessary panic!