I used our free minutes to make calls and text through Whatsapp also. Whatsapp is easy, you download it ahead of time, invite the people you want to keep in contact with so they can download the app also. Then when you want to make a call, log onto your free wifi and open the app and either call or text those people. You can't call people who don't use Whatsapp. I didn't try the wifi calling, but have used it when I was in foreign countries and used the hotel wifi and it worked fine. In theory I don't see any reason it wouldn't work. But I will tell you that the free wifi on the ship wasn't as reliable as say a hotel wifi. Even using whatsapp, sometimes the call wouldn't go through or I would have to call 2-3 times to finish a conversation. Most of the time it was fine though for a few minutes conversation. If you must have reliable phone service I would check your phone company to see if they offer anything and then check with the cruiseline to see if your ship offers the newer Starlink wifi. I know a lot of people travel and pay a lot of money to have streaming capabilities so they will have more reliable service.