A:Answer If your I Phone is with you you will get the same texts and calls on your Series 4 GPS watch as on your phone (iphone 6 or greater is required). The more expensive Series 4 GPS plus cellular model, distinguished by a red ring on the watch knob, allows you to recieve calls and texts without having your phone with you—like if you are going on a run and don’t want to bring your phone phone along. Of course, you pay a monthly fee for this convenience.