Can you track someone else's iphone without them knowing?

Can you track someone else's iphone without them knowing?

Wouldn't surprise me…

Actually, my mother did download an app that allowed her phone to track my father's and brother's phones. But this only works if you download the app on THEIR phone and they don't delete it. I don't know what app it was.

Technically… Yes… If you had the $$$$$$$$$$$$$$ to get the hardware and software from a spy shop

if not, then no…