Magic Jack app to call home ?

I'm wondering if I turn off my roaming will this app work in Negril to call home?

My understanding is it will. My husband will be trying it on our next trip in April!

I've been trying to have somebody I've called in the states tell me anything other than I sound distorted/broken up/garbbled. These calls have been made from the West End with either Iwireless or Digicell internet. That said I go to my Digicell phone. In other words...good luck.