Soon, Model S/X owners will be able to leave their key fob at home. In a tweet, Musk said the Model S and X will soon get the same keyless smartphone entry that the Model 3 has:https://electrek.co/2018/05/10/tesla-model-s-model-x-keyless-phone-entry-like-model-3/
I am not surprised. I've been thinking for awhile now that Tesla will gradually shift to using the smartphone app more for all cars, because Tesla sees it as the future, especially with the coming Tesla Network. I can see Tesla wanting to create that all-around smartphone experience where users can do everything from summoning their car to even sharing their car with other users via the app in the future.