Franco I [just] checked the permissions of Accressant application, i see: network, sensor and notifications.
What other information could be sent to the server?
In theory, any of the myriad things an app can find out on Android. Device model, amount of free storage space, time zone, SIM country code...
To be clear, I am not claiming anything like that is happening! But the fundamental difference between client-side filtering and server-side is that server-side filtering involves the client sending information to the server.