My wife and I each have a Galaxy s5 and we use Verizon's network. We want to leave one phone at home, positioned with the screen aimed towards the dog crate area. We want to be able to call that phone from the second phone and have it act as a "nanny cam" of sorts only for the duration of the call. Obviously, to limit data use, it's important for me to have the "nanny cam phone" active only during the the call. And also I should add that "nanny cam phone" will not be dedicated for this purpose but must return to it's primary role as a phone after we return home. Does anyone know how to make this happen? Is there an app for this?