I have had a Republic Wireless cell phone here in the States for about 10 years. You have to buy a phone, monthly fee is $22. It is an internet based calling system backed up by Sprint when not connected to the internet. This cell phone system will work in the Caribbean, Latin and South America when you are connected to the internet ( wifi hot spot). No additional charges. If someone calls your US number on this system your phone will ring in other countries. And if you call a US based number from out of the US you will connect. What you cannot do is call a SXM number on or off island.

Wendell