It's quite interesting to hear people say they find it creepy, or invasive.
Me too.
We've had Find Friends as a family for about 9 months now. I've used it twice to check how far DH is from home. He works between offices in three different counties and I can never remember which one he said he was going to on any given day if he's even told me. I also prefer him not to have to answer the phone when driving, even with his hands free system. I accept that he will take work calls while driving but I just don't want to add to it.
I've also used it about four times to see where adult DD1 is. She rides other people's horses for them. If she's hacking out alone, she will tell me roughly where she's going and when she's likely to be back. She isn't going to answer her phone while riding so, if she's late, it's helpful to check where she is and that her dot is moving. That's enough for me to know she hasn't been chucked off and injured.
DD1 has also used it to tell DD2 how to find her way home after she stormed off in a strop with the dog and got lost in some unfamiliar fields a fair distance away. She'd have got home eventually but the dog is unwell and she'd gone in the wrong footwear and was getting upset about being lost.
In that time DH hasn't ever checked up on me. I just mentioned how MNers would think we are freaks for having it and that reminded DH to ask DD1 to show him where it is on his phone.
I don't know why people think having it means you will track where your DH is every minute of the day. I'd have to keep looking all the time to do that and, quite frankly, I'm not interested enough. I have access to his post every day but I don't open it, even though he wouldn't bat an eyelid if I did. He freely tells me the code to unlock his phone but I never remember it and have never tried to use it to check up on him.
I completely see how this app could be used by a coercive controller but I just don't get how it's creepy in a healthy relationship.