Hi, I'm a newbie. For the life of me I can't figure out how to get my WIFI CALLING feature to work. I can get internet access easy. It works great, but no wi-fi calling. I have scoured the internet, watched tons of videos, talked to countless reps and get a different answer every time. Some people say I have to have an app like Skype in order to take advantage of this feature. Others say "not at all." The Nokia website itself doesn't mention anything like having to have an app to make this feature work. Is there a specific T-Mobile plan I need to make this work. I'm currently on a $50/mo.no contract plan. What's the secret to take advantage of this neat feature. If anybody could help, I'd appreciate it greatly. Need to know soon, otherwise the phone goes back to T-Mobile for return and cancellation. Thanks.