I currently have a 6 Plus, I plan on getting a 6 in the near future to try out the smaller size but would like to add it as a second phone with its own service. Now during the summer I like to have a life proof case on my phone as Im always by the pool or the beach or doing other outdoor activities. But I don't like the life proof case any other time cause of its size. Now if I were to sign in with the same apple id account on two iPhones would they be able to work in unison? Example my "real" number is associated with my 6+ but if Im at the beach with my 6 in its life proof case and left my 6+ at home and a message gets sent to my real number will it also be sent to my 6? Would there be a way to do that with phone calls as well like how my iPad rings when my phone rings?