Does the contract free (Tmobile) iphone 5S works with any GSM company worldwide?

A friend is travelling to USA in a couple of days and I gave her money to get me the new iphone, she will be there only until october 13th and I need to now if the contract free Tmobile iphone will work with a GSM from my local Carrier (movistar, Ecuador) please, I'll give all the points and stars available to the best answer.

Ya it will work with any sim card. So just buy t-mob contract free phone.

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