Retrieve some kind of unique key/signature that can be read in android app if only installed only from play store.
The closest I got to was "https://developers.google.com/instance-id/guides/android-implementation" which seems exactly what I want but I'm still trying to wrap my head around it. It seems that you can create tokens but I don't want the token to change each time I get it !!
I want to use this key to decrypt a string but don't want the key to be in the app.