Andrew was a part of Caine's crew, often following him around. In Gone he is described as a dark skinned, kind of tall teenager. Andrew was taped during his 'poof' by Computer Jack, on Caine's orders. Andrew had the Power to send shock waves from his hands. They basically destroyed everything nearby, including a brick wall. Diana says in Gone, "That's a lot of damage for a three bar."
When Andrew poofed, Caine tied him up and Computer Jack was able to catch the moment he poofed on video. Later, when the video was rewinded and slowed down they saw a green orb with lots of teeth reaching out to Andrew. They found out that the person "Poofing" sees something that tempts them, a mother, a father, a sister. In their mind, it looks like a familiar loved one. To the rest of the world, it seems to be a green monster with teeth. Andrew is never seen again, but Computer Jack attempts to tell Sam how to beat his poof by learning from Andrew's.
In the books Lies and Fear it is never mentioned that he poofed out of the FAYZ into the outside world.