Do I need to have physical access to the device to install the software?

You must own the device you intend to monitor and have physical access to install the software. The software is only to be used by parents and employers with proper consent to monitor the phone.

The software is downloaded directly onto the device to be monitored. Remote installation is not possible.

Here you can have more details about how to install the software on Android OS:
http://thetruthspy.com/how-to-install-mobile-spy-on-android-with-thetruthspy/

Joe