Yeah I actually wish Brian and I had tracking devices for each other. There was one day he had to drive two hours away to a client and the weather was bad. I tried calling him multiple times and texting him and it is NOT like him to not respond. I tried every way to get a hold of him I could think of and even called his office to see if they had heard from him. I was really worried and had worked myself into complete panic mode. Turns out he had put his phone in vibrate and completely forgot that the ringer was off. I wouldn't have used it being all "where were you ad what were you doing" but seeing that he had made it would have really put my mind at ease when i was totally losing my mind with worry.
IMO they are worth their weight in gold for these kinds of things alone.
It's not a nosy thing, a "I want to know where you are all the times so I can control you!" thing.. it's a safety and peace of mind thing.
I am forgetful, my whole family travels a lot, we live states/countries away from each other at times.. it's not even necessarily that we are in danger but especially when it comes to travel.. you are tired, you get someplace, you land face first into a bed and forget to call anyone. and while you are snoozing.. your family member/spouse is FREAKING OUT thinking your plane crashed, your car crashed, you didn't arrive safely etc.. at least with this they can know you are home/at a hotel and save themselves the worry.
IMO in a situation without trust.. of course these tools can be abused. As can most things (facebook, email, hiring private investigators lol etc..) but used with people you trust, it's a really useful tool.
I can honest to goodness say my parents never over-stepped or abused it. We trust each other and I told them where I was anyway.
I know since I moved away my mom probably checks to see I am home safely at night and it doesn't bother me. She doesn't do it because she's nosey or wants to know where I am in a controlling way.. I live in the city and she wants to know I'm safe and frankly.. I'm glad I have someone who cares enough to check my GPS tracker to make sure I'm safe and sound at the end of the night lol