I got that S5 and am using it on wifi, no sim card. It mostly works, but not everything does. For example, I have tried to use talkatone for phone calls, but it won't let me. It asks for email address but then claims suspicious activity. Meanwhile, I can't get email on the phone. google says to enter an email address, then "checks info" and says to try again later. I have, always with the same result. Am I detecting a pattern here? Is google deliberately trying to hold me back because it's mad that I don't have a sim card? At least for now, I have no plans to buy one. How can I make phone calls and get email without resorting to sim?