Recently off the Emerald & had asked Guest Services where to get more info on the add items on the PLUS. The Premium Deserts are available at Coffee & Cones on Lido Deck 15. They are fancy pre-made ice cream sundaes.
I have Google Fi as phone carrier on Android and can send & receive text & phone calls over the ship wifi (INTERner) I cannot do the same to someone on board the ship unless he/she also have similar set up on phone.