You can spy on a phone in the following ways:
- Track the GPS location of the device by using Google’s Find My Phone or Apple’s Find My iPhone. Or, by using the services within a mobile provider, such as AT&T, Verizon;
- Track SMS by associating the phone number with Google Voice one;
- Spy on SMS, instant messengers like Facebook one, calls, websites, bookmarks – the entire Internet activity – by using spyware.