A:AnswerYou would need to get a new BYOD sim from Straight Talk as this phone is GSM based. It uses either the AT&T or T-Mobile towers in your area. Outside of that, you should be fine. Double check the coverage maps for both AT&T and T-Mobile and see what is the strongest carrier and get the BYOD sim for that carrier. You call also call Straight Talk and see what they recommend.
A:AnswerI use FB and FBmessenger on it without any issues. It works well on both wifi and 4G. I have 3G RAM, 32G internal memory and 64G microSD installed.