Dmitry, good afternoon. But how to practically install the application without access to the device?
Almost nothing !!! If a person is careful, attentive, never leaves his smartphone anywhere, then installing such a program is not possible.
In order to install such a program on a smartphone, you need to get the smartphone in your hands for a certain time (not five and not ten minutes),
to have time to install and configure the program. And in order to access your smartphone from a distance - this event requires other knowledge in
field of IT technology. And in order to take such a risk - it must be economically justified. The only option is such a program
it is possible to establish a minor child with the written consent of his parents.