How to spy on an Android phone from PC for free?

It is doable to spy on an Android phone from any device, including PC, provided there’s the Internet connection. Google allows to spy on the phone’s GPS location if it is associated with Gmail and can be tracked with Find My Phone. This option is free. Apple provides Find My iPhone with the same approach toward GPS location.
Also, mobile providers like Verizon suggest accounts to track the phone’s GPS location and find out the details about SMS. Users access an online account from PC or any other device and track the information anticipated within the service.
If willing to fish for more personal information, spyware is more effective. However, the service is paid.