Android - activate features of companion PC app if running 'purchased' version

I've got two Android apps, one free, the other paid. In order to function they require that a PC app be active and running on the same network as the android phone.

I'd like to come up with a way to activate more features on the PC app if I am able to detect the paid version of the app running on the phone.

I know a simple way would just to have the paid app talk to the companion app on the pc and simply tell it that it's a paid version. However, what I'd really like to do is somehow get a unique device ID and verify that it has purchased the app -- is there a 开发者_如何转开发way to confirm it somehow with google? Or any other way I can securely do this?