Wrong. If they are married, it's THEIR phone, and he can install the app on it if he likes.
Please just stop talking out of your ass when you clearly have no idea about what is or isn't legal in this situation.
Obviously you don't know the difference between shared property like the house and other assets, and personal items, like clothing, jewelry, cell phones, shoes, pets, etc.
In a divorce, you can take half your wife's clothes? No.
He gave her a GPS device with the intent of surreptitiously tracking her. It falls under federal as well as many state's laws. Anyone who thinks that's legal is crazy.
From the article:
http://www.rmtracking.com/is-gps-vehicle-tracking-legal.php
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What is an illegal use of GPS?>>
<<Using a gps (or any other surveillance device) to surreptitiously track another person or another’s vehicle may be illegal if such tracking constitutes “stalking.” In a Colorado Case “People v. Sullivan” use of a gps on a spouse’s automobile was deemed to be stalking because the spouse who attached the gps to the car did it (a) without the knowledge of the other spouse; (b) for the purpose of tracking the spouse’s movements or to acquire information about the spouse’s whereabouts and activities.>>
This is from an attorney not my ass no matter how much you disagree. So unless you can quote an attorney, you are the one talking out of your ass.
Intent is critical. Based on the OP statement above, his intent was to track her using a tracking device without her knowledge. Leave cars out of this, it was on her person, not a car.
I still say the whole thing is BS anyway.