Who is Skylar?

Yes, Skylar was another AI. She was unaware that she was an AI program and was used in forcing Nick into removing the Live Wire program from the government's project. As for who created her, it is suggested that Neville did because he aparently knew about what she was (he even refered to her as a tool during their face off in the train). The fact that the Game that Nick and everyone else plays is runned by Neville, who also is involved with the weather controling system. And the reason why she aided in stopping Neville was her making up for the wrong she did.

But this one's eating my popcorn!