Install NoRoot Firewall as HenryBemis mentioned, it's on the Play store. The app tells you what IP addresses apps are trying to communicate with in a fairly neat and simple way.
I've just installed it on my 6.1 Plus. Nothing sus yet but it's only been 5 minutes.
I've just installed it on my 6.1 Plus. Nothing sus yet but it's only been 5 minutes.